21662645636268 has 144 divisors (see below), whose sum is σ = 67925567324160. Its totient is φ = 5668239088512.

The previous prime is 21662645636267. The next prime is 21662645636273. The reversal of 21662645636268 is 86263654626612.

21662645636268 is a `hidden beast` number, since 2 + 1 + 6 + 6 + 2 + 6 + 4 + 563 + 6 + 2 + 68 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (21662645636267) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 25617528 + ... + 26449631.

It is an arithmetic number, because the mean of its divisors is an integer number (471705328640).

Almost surely, 2^{21662645636268} is an apocalyptic number.

21662645636268 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21662645636268 is an abundant number, since it is smaller than the sum of its proper divisors (46262921687892).

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

21662645636268 is a wasteful number, since it uses less digits than its factorization.

21662645636268 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52067316 (or 52067311 counting only the distinct ones).

The product of its digits is 179159040, while the sum is 63.

The spelling of 21662645636268 in words is "twenty-one trillion, six hundred sixty-two billion, six hundred forty-five million, six hundred thirty-six thousand, two hundred sixty-eight".