21086372 has 12 divisors (see below), whose sum is σ = 37040220. Its totient is φ = 10503456.

The previous prime is 21086347. The next prime is 21086381. The reversal of 21086372 is 27368012.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 4227136 + 16859236 = 2056^2 + 4106^2 .

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, 8723 + ... + 10874.

It is an arithmetic number, because the mean of its divisors is an integer number (3086685).

Almost surely, 2^21086372 is an apocalyptic number.

It is an amenable number.

21086372 is a deficient number, since it is larger than the sum of its proper divisors (15953848).

21086372 is a wasteful number, since it uses less digits than its factorization.

21086372 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19870 (or 19868 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 29.

The square root of 21086372 is about 4591.9899825675. The cubic root of 21086372 is about 276.2701443784.

The spelling of 21086372 in words is "twenty-one million, eighty-six thousand, three hundred seventy-two".