21496923 has 24 divisors (see below), whose sum is σ = 37356800. Its totient is φ = 11636784.

The previous prime is 21496913. The next prime is 21496939. The reversal of 21496923 is 32969412.

It is not a de Polignac number, because 21496923 - 2¹⁶ = 21431387 is a prime.

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

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21496903) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7783 + ... + 10176.

Almost surely, 2^21496923 is an apocalyptic number.

21496923 is a deficient number, since it is larger than the sum of its proper divisors (15859877).

21496923 is a wasteful number, since it uses less digits than its factorization.

21496923 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17991 (or 17988 counting only the distinct ones).

The product of its digits is 23328, while the sum is 36.

The square root of 21496923 is about 4636.4774344323. The cubic root of 21496923 is about 278.0516224891.

The spelling of 21496923 in words is "twenty-one million, four hundred ninety-six thousand, nine hundred twenty-three".