21756536460 has 72 divisors (see below), whose sum is σ = 66096248400. Its totient is φ = 5792827008.

The previous prime is 21756536429. The next prime is 21756536489. The reversal of 21756536460 is 6463565712.

21756536460 is a `hidden beast` number, since 2 + 1 + 7 + 56 + 536 + 4 + 60 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 24991 + ... + 210089.

It is an arithmetic number, because the mean of its divisors is an integer number (918003450).

Almost surely, 2^21756536460 is an apocalyptic number.

21756536460 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21756536460 is an abundant number, since it is smaller than the sum of its proper divisors (44339711940).

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

21756536460 is a wasteful number, since it uses less digits than its factorization.

21756536460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185767 (or 185762 counting only the distinct ones).

The product of its (nonzero) digits is 907200, while the sum is 45.

The spelling of 21756536460 in words is "twenty-one billion, seven hundred fifty-six million, five hundred thirty-six thousand, four hundred sixty".