21531658160 has 20 divisors (see below), whose sum is σ = 50061105408. Its totient is φ = 8612663232.

The previous prime is 21531658157. The next prime is 21531658171. The reversal of 21531658160 is 6185613512.

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

It is a super-2 number, since 2×21531658160² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 134572784 + ... + 134572943.

Almost surely, 2^21531658160 is an apocalyptic number.

21531658160 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21531658160 is an abundant number, since it is smaller than the sum of its proper divisors (28529447248).

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

21531658160 is a wasteful number, since it uses less digits than its factorization.

21531658160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 269145740 (or 269145734 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 38.

The spelling of 21531658160 in words is "twenty-one billion, five hundred thirty-one million, six hundred fifty-eight thousand, one hundred sixty".