21632560 has 20 divisors (see below), whose sum is σ = 50295888. Its totient is φ = 8652992.

The previous prime is 21632557. The next prime is 21632563. The reversal of 21632560 is 6523612.

It is an interprime number because it is at equal distance from previous prime (21632557) and next prime (21632563).

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (21632563) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 135124 + ... + 135283.

Almost surely, 2^21632560 is an apocalyptic number.

21632560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21632560 is an abundant number, since it is smaller than the sum of its proper divisors (28663328).

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

21632560 is a wasteful number, since it uses less digits than its factorization.

21632560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 270420 (or 270414 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 21632560 is about 4651.0815946401. The cubic root of 21632560 is about 278.6351950702.

The spelling of 21632560 in words is "twenty-one million, six hundred thirty-two thousand, five hundred sixty".