CSS

get rid of arrows number input

input[type=number]::-webkit-inner-spin-button, 
input[type=number]::-webkit-outer-spin-button { 
  -webkit-appearance: none; 
  margin: 0; 
}

input number hide arrows

/* hide arrows
 Chrome, Safari, Edge, Opera */
input::-webkit-outer-spin-button,
input::-webkit-inner-spin-button {
  -webkit-appearance: none !important;
  margin: 0 !important;
}

/* Firefox */
input[type=number] {
  -moz-appearance: textfield !important;
}

remove arrows input number

input[type=number]::-webkit-inner-spin-button,
input[type=number]::-webkit-outer-spin-button { 
	-webkit-appearance: none;
}

remove numericUpDown arrows

numericUpDown1.Controls.RemoveAt(0);