21568980 has 24 divisors (see below), whose sum is σ = 60393312. Its totient is φ = 5751712.

The previous prime is 21568979. The next prime is 21568999. The reversal of 21568980 is 8986512.

It is a congruent number.

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, 179682 + ... + 179801.

It is an arithmetic number, because the mean of its divisors is an integer number (2516388).

Almost surely, 2^21568980 is an apocalyptic number.

21568980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21568980 is an abundant number, since it is smaller than the sum of its proper divisors (38824332).

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

21568980 is a wasteful number, since it uses less digits than its factorization.

21568980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 359495 (or 359493 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 39.

The square root of 21568980 is about 4644.2415957829. The cubic root of 21568980 is about 278.3619494006.

The spelling of 21568980 in words is "twenty-one million, five hundred sixty-eight thousand, nine hundred eighty".