21662645636287 has 2 divisors, whose sum is σ = 21662645636288. Its totient is φ = 21662645636286.

The previous prime is 21662645636279. The next prime is 21662645636321. The reversal of 21662645636287 is 78263654626612.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21662645636287 - 2³ = 21662645636279 is a prime.

It is a super-3 number, since 3×21662645636287³ (a number of 41 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21662645636267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10831322818143 + 10831322818144.

It is an arithmetic number, because the mean of its divisors is an integer number (10831322818144).

Almost surely, 2^{21662645636287} is an apocalyptic number.

21662645636287 is a deficient number, since it is larger than the sum of its proper divisors (1).

21662645636287 is an equidigital number, since it uses as much as digits as its factorization.

21662645636287 is an evil number, because the sum of its binary digits is even.

The product of its digits is 209018880, while the sum is 64.

The spelling of 21662645636287 in words is "twenty-one trillion, six hundred sixty-two billion, six hundred forty-five million, six hundred thirty-six thousand, two hundred eighty-seven".