21276723 has 16 divisors (see below), whose sum is σ = 30665376. Its totient is φ = 13044480.

The previous prime is 21276683. The next prime is 21276727. The reversal of 21276723 is 32767212.

It is not a de Polignac number, because 21276723 - 2⁸ = 21276467 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (21276727) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11503 + ... + 13223.

It is an arithmetic number, because the mean of its divisors is an integer number (1916586).

Almost surely, 2^21276723 is an apocalyptic number.

21276723 is a deficient number, since it is larger than the sum of its proper divisors (9388653).

21276723 is a wasteful number, since it uses less digits than its factorization.

21276723 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2054.

The product of its digits is 7056, while the sum is 30.

The square root of 21276723 is about 4612.6698342717. The cubic root of 21276723 is about 277.0989710937.

The spelling of 21276723 in words is "twenty-one million, two hundred seventy-six thousand, seven hundred twenty-three".