21725560 has 16 divisors (see below), whose sum is σ = 48882600. Its totient is φ = 8690208.

The previous prime is 21725551. The next prime is 21725567. The reversal of 21725560 is 6552712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21725567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 271530 + ... + 271609.

Almost surely, 2^21725560 is an apocalyptic number.

21725560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21725560 is an abundant number, since it is smaller than the sum of its proper divisors (27157040).

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

21725560 is a wasteful number, since it uses less digits than its factorization.

21725560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 543150 (or 543146 counting only the distinct ones).

The product of its (nonzero) digits is 4200, while the sum is 28.

The square root of 21725560 is about 4661.0685470179. The cubic root of 21725560 is about 279.0339154481.

The spelling of 21725560 in words is "twenty-one million, seven hundred twenty-five thousand, five hundred sixty".