21463980 has 24 divisors (see below), whose sum is σ = 60099312. Its totient is φ = 5723712.

The previous prime is 21463969. The next prime is 21463999. The reversal of 21463980 is 8936412.

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, 178807 + ... + 178926.

It is an arithmetic number, because the mean of its divisors is an integer number (2504138).

Almost surely, 2^21463980 is an apocalyptic number.

21463980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21463980 is an abundant number, since it is smaller than the sum of its proper divisors (38635332).

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

21463980 is a wasteful number, since it uses less digits than its factorization.

21463980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 357745 (or 357743 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 21463980 is about 4632.9234830720. The cubic root of 21463980 is about 277.9095162972.

The spelling of 21463980 in words is "twenty-one million, four hundred sixty-three thousand, nine hundred eighty".