21897124 has 12 divisors (see below), whose sum is σ = 38356864. Its totient is φ = 10938024.

The previous prime is 21897097. The next prime is 21897133. The reversal of 21897124 is 42179812.

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 21897124.

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, 3769 + ... + 7615.

Almost surely, 2^21897124 is an apocalyptic number.

It is an amenable number.

21897124 is a deficient number, since it is larger than the sum of its proper divisors (16459740).

21897124 is a wasteful number, since it uses less digits than its factorization.

21897124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5274 (or 5272 counting only the distinct ones).

The product of its digits is 8064, while the sum is 34.

The square root of 21897124 is about 4679.4362908367. The cubic root of 21897124 is about 279.7664889869.

The spelling of 21897124 in words is "twenty-one million, eight hundred ninety-seven thousand, one hundred twenty-four".