21540992 has 32 divisors (see below), whose sum is σ = 46818000. Its totient is φ = 9790720.

The previous prime is 21540983. The next prime is 21541019. The reversal of 21540992 is 29904512.

It is a tau number, because it is divible by the number of its divisors (32).

It is a Harshad number since it is a multiple of its sum of digits (32).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6242 + ... + 9057.

Almost surely, 2^21540992 is an apocalyptic number.

21540992 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21540992 is an abundant number, since it is smaller than the sum of its proper divisors (25277008).

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

21540992 is a wasteful number, since it uses less digits than its factorization.

21540992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15324 (or 15312 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 32.

The square root of 21540992 is about 4641.2274238611. The cubic root of 21540992 is about 278.2414960697.

The spelling of 21540992 in words is "twenty-one million, five hundred forty thousand, nine hundred ninety-two".