21368580 has 24 divisors (see below), whose sum is σ = 59832192. Its totient is φ = 5698272.

The previous prime is 21368569. The next prime is 21368591. The reversal of 21368580 is 8586312.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21368569) and next prime (21368591).

It is a super-2 number, since 2×21368580² = 913232422432800, which contains 22 as substring.

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, 178012 + ... + 178131.

It is an arithmetic number, because the mean of its divisors is an integer number (2493008).

Almost surely, 2^21368580 is an apocalyptic number.

21368580 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21368580 is an abundant number, since it is smaller than the sum of its proper divisors (38463612).

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

21368580 is a wasteful number, since it uses less digits than its factorization.

21368580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 356155 (or 356153 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 33.

The square root of 21368580 is about 4622.6161424025. The cubic root of 21368580 is about 277.4971674088.

The spelling of 21368580 in words is "twenty-one million, three hundred sixty-eight thousand, five hundred eighty".