21386004 has 12 divisors (see below), whose sum is σ = 49900704. Its totient is φ = 7128664.

The previous prime is 21385999. The next prime is 21386047. The reversal of 21386004 is 40068312.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×21386004² = 914722334176032, which contains 22 as substring.

It is a congruent number.

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, 891072 + ... + 891095.

It is an arithmetic number, because the mean of its divisors is an integer number (4158392).

Almost surely, 2^21386004 is an apocalyptic number.

It is an amenable number.

21386004 is an abundant number, since it is smaller than the sum of its proper divisors (28514700).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21386004 is a wasteful number, since it uses less digits than its factorization.

21386004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1782174 (or 1782172 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 21386004 is about 4624.5004054492. The cubic root of 21386004 is about 277.5725709070.

The spelling of 21386004 in words is "twenty-one million, three hundred eighty-six thousand, four".