21387010 has 16 divisors (see below), whose sum is σ = 40170816. Its totient is φ = 8182768.

The previous prime is 21387001. The next prime is 21387059. The reversal of 21387010 is 1078312.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46264 + ... + 46723.

It is an arithmetic number, because the mean of its divisors is an integer number (2510676).

Almost surely, 2^21387010 is an apocalyptic number.

21387010 is a deficient number, since it is larger than the sum of its proper divisors (18783806).

21387010 is a wasteful number, since it uses less digits than its factorization.

21387010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93017.

The product of its (nonzero) digits is 336, while the sum is 22.

The square root of 21387010 is about 4624.6091726761. The cubic root of 21387010 is about 277.5769231870.

The spelling of 21387010 in words is "twenty-one million, three hundred eighty-seven thousand, ten".