21662645636267 has 2 divisors, whose sum is σ = 21662645636268. Its totient is φ = 21662645636266.

The previous prime is 21662645636221. The next prime is 21662645636273. The reversal of 21662645636267 is 76263654626612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21662645636267 - 2¹² = 21662645632171 is a prime.

It is not a weakly prime, because it can be changed into another prime (21662645636287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10831322818133 + 10831322818134.

It is an arithmetic number, because the mean of its divisors is an integer number (10831322818134).

Almost surely, 2^{21662645636267} is an apocalyptic number.

21662645636267 is a deficient number, since it is larger than the sum of its proper divisors (1).

21662645636267 is an equidigital number, since it uses as much as digits as its factorization.

21662645636267 is an evil number, because the sum of its binary digits is even.

The product of its digits is 156764160, while the sum is 62.

The spelling of 21662645636267 in words is "twenty-one trillion, six hundred sixty-two billion, six hundred forty-five million, six hundred thirty-six thousand, two hundred sixty-seven".