21540720560 has 40 divisors (see below), whose sum is σ = 50153749776. Its totient is φ = 8603974400.

The previous prime is 21540720529. The next prime is 21540720563. The reversal of 21540720560 is 6502704512.

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (21540720563) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 135974 + ... + 248133.

Almost surely, 2^21540720560 is an apocalyptic number.

21540720560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21540720560 is an abundant number, since it is smaller than the sum of its proper divisors (28613029216).

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

21540720560 is a wasteful number, since it uses less digits than its factorization.

21540720560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 384821 (or 384815 counting only the distinct ones).

The product of its (nonzero) digits is 16800, while the sum is 32.

The spelling of 21540720560 in words is "twenty-one billion, five hundred forty million, seven hundred twenty thousand, five hundred sixty".