21434928 has 20 divisors (see below), whose sum is σ = 55373688. Its totient is φ = 7144960.

The previous prime is 21434921. The next prime is 21434939. The reversal of 21434928 is 82943412.

It is a super-2 number, since 2×21434928² = 918912276730368, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21434921) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 223233 + ... + 223328.

Almost surely, 2^21434928 is an apocalyptic number.

It is an amenable number.

21434928 is an abundant number, since it is smaller than the sum of its proper divisors (33938760).

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

21434928 is a wasteful number, since it uses less digits than its factorization.

21434928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 446572 (or 446566 counting only the distinct ones).

The product of its digits is 13824, while the sum is 33.

The square root of 21434928 is about 4629.7870361389. The cubic root of 21434928 is about 277.7840740025.

The spelling of 21434928 in words is "twenty-one million, four hundred thirty-four thousand, nine hundred twenty-eight".