21896969491980 has 288 divisors, whose sum is σ = 79196246857728. Its totient is φ = 4834935244800.

The previous prime is 21896969491829. The next prime is 21896969492017. The reversal of 21896969491980 is 8919496969812.

21896969491980 is a `hidden beast` number, since 2 + 1 + 8 + 9 + 69 + 69 + 491 + 9 + 8 + 0 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 21896969491980.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 9449022 + ... + 11535941.

It is an arithmetic number, because the mean of its divisors is an integer number (274986968256).

Almost surely, 2^{21896969491980} is an apocalyptic number.

21896969491980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21896969491980 is an abundant number, since it is smaller than the sum of its proper divisors (57299277365748).

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

21896969491980 is a wasteful number, since it uses less digits than its factorization.

21896969491980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20985037 (or 20985032 counting only the distinct ones).

The product of its (nonzero) digits is 1088391168, while the sum is 81.

The spelling of 21896969491980 in words is "twenty-one trillion, eight hundred ninety-six billion, nine hundred sixty-nine million, four hundred ninety-one thousand, nine hundred eighty".