21928023 has 16 divisors (see below), whose sum is σ = 34985440. Its totient is φ = 13493952.

The previous prime is 21928001. The next prime is 21928043. The reversal of 21928023 is 32082912.

It is a happy number.

It is not a de Polignac number, because 21928023 - 2⁹ = 21927511 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21928043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30886 + ... + 31587.

It is an arithmetic number, because the mean of its divisors is an integer number (2186590).

Almost surely, 2^21928023 is an apocalyptic number.

21928023 is a deficient number, since it is larger than the sum of its proper divisors (13057417).

21928023 is a wasteful number, since it uses less digits than its factorization.

21928023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62495 (or 62489 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 21928023 is about 4682.7366998370. The cubic root of 21928023 is about 279.8980198346.

The spelling of 21928023 in words is "twenty-one million, nine hundred twenty-eight thousand, twenty-three".