21587372 has 12 divisors (see below), whose sum is σ = 37944480. Its totient is φ = 10746096.

The previous prime is 21587347. The next prime is 21587381. The reversal of 21587372 is 27378512.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10868 + ... + 12699.

It is an arithmetic number, because the mean of its divisors is an integer number (3162040).

Almost surely, 2^21587372 is an apocalyptic number.

It is an amenable number.

21587372 is a deficient number, since it is larger than the sum of its proper divisors (16357108).

21587372 is a wasteful number, since it uses less digits than its factorization.

21587372 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23800 (or 23798 counting only the distinct ones).

The product of its digits is 23520, while the sum is 35.

The square root of 21587372 is about 4646.2212603362. The cubic root of 21587372 is about 278.4410472297.

The spelling of 21587372 in words is "twenty-one million, five hundred eighty-seven thousand, three hundred seventy-two".