21520672545740 has 24 divisors (see below), whose sum is σ = 45196769772000. Its totient is φ = 8607629508608.

The previous prime is 21520672545703. The next prime is 21520672545761. The reversal of 21520672545740 is 4754527602512.

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, 39693365 + ... + 40231884.

It is an arithmetic number, because the mean of its divisors is an integer number (1883198740500).

Almost surely, 2^{21520672545740} is an apocalyptic number.

21520672545740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21520672545740 is an abundant number, since it is smaller than the sum of its proper divisors (23676097226260).

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

21520672545740 is a wasteful number, since it uses less digits than its factorization.

21520672545740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79938721 (or 79938719 counting only the distinct ones).

The product of its (nonzero) digits is 4704000, while the sum is 50.

The spelling of 21520672545740 in words is "twenty-one trillion, five hundred twenty billion, six hundred seventy-two million, five hundred forty-five thousand, seven hundred forty".