21712492 has 12 divisors (see below), whose sum is σ = 38189200. Its totient is φ = 10801296.

The previous prime is 21712477. The next prime is 21712513. The reversal of 21712492 is 29421712.

It is a self number, because there is not a number n which added to its sum of digits gives 21712492.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 12843 + ... + 14434.

Almost surely, 2^21712492 is an apocalyptic number.

It is an amenable number.

21712492 is a deficient number, since it is larger than the sum of its proper divisors (16476708).

21712492 is a wasteful number, since it uses less digits than its factorization.

21712492 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27480 (or 27478 counting only the distinct ones).

The product of its digits is 2016, while the sum is 28.

The square root of 21712492 is about 4659.6665116723. Note that the first 3 decimals coincide. The cubic root of 21712492 is about 278.9779576031.

The spelling of 21712492 in words is "twenty-one million, seven hundred twelve thousand, four hundred ninety-two".