21921492 has 24 divisors (see below), whose sum is σ = 51233056. Its totient is φ = 7295328.

The previous prime is 21921481. The next prime is 21921533. The reversal of 21921492 is 29412912.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9483 + ... + 11565.

Almost surely, 2^21921492 is an apocalyptic number.

It is an amenable number.

21921492 is an abundant number, since it is smaller than the sum of its proper divisors (29311564).

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

21921492 is a wasteful number, since it uses less digits than its factorization.

21921492 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2967 (or 2965 counting only the distinct ones).

The product of its digits is 2592, while the sum is 30.

The square root of 21921492 is about 4682.0392992797. The cubic root of 21921492 is about 279.8702289802.

The spelling of 21921492 in words is "twenty-one million, nine hundred twenty-one thousand, four hundred ninety-two".