21923928 has 96 divisors (see below), whose sum is σ = 65192400. Its totient is φ = 6614784.

The previous prime is 21923917. The next prime is 21923947. The reversal of 21923928 is 82932912.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 21923892 and 21923901.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 55026 + ... + 55422.

Almost surely, 2^21923928 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21923928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32596200).

21923928 is an abundant number, since it is smaller than the sum of its proper divisors (43268472).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21923928 is a wasteful number, since it uses less digits than its factorization.

21923928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 481 (or 474 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 21923928 is about 4682.2994351066. The cubic root of 21923928 is about 279.8805953462.

The spelling of 21923928 in words is "twenty-one million, nine hundred twenty-three thousand, nine hundred twenty-eight".