21161420262972 has 144 divisors (see below), whose sum is σ = 63146595762432. Its totient is φ = 6133744932480.

The previous prime is 21161420262967. The next prime is 21161420262973. The reversal of 21161420262972 is 27926202416112.

21161420262972 is a `hidden beast` number, since 2 + 1 + 1 + 6 + 14 + 2 + 0 + 2 + 629 + 7 + 2 = 666.

It is a super-2 number, since 2×21161420262972² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21161420262973) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 42779793 + ... + 43271624.

It is an arithmetic number, because the mean of its divisors is an integer number (438518026128).

Almost surely, 2^{21161420262972} is an apocalyptic number.

21161420262972 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21161420262972 is an abundant number, since it is smaller than the sum of its proper divisors (41985175499460).

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

21161420262972 is a wasteful number, since it uses less digits than its factorization.

21161420262972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86051470 (or 86051456 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The spelling of 21161420262972 in words is "twenty-one trillion, one hundred sixty-one billion, four hundred twenty million, two hundred sixty-two thousand, nine hundred seventy-two".