21867166577 has 2 divisors, whose sum is σ = 21867166578. Its totient is φ = 21867166576.

The previous prime is 21867166567. The next prime is 21867166627. The reversal of 21867166577 is 77566176812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19662770176 + 2204396401 = 140224^2 + 46951^2 .

It is a cyclic number.

It is not a de Polignac number, because 21867166577 - 2¹² = 21867162481 is a prime.

It is not a weakly prime, because it can be changed into another prime (21867166547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10933583288 + 10933583289.

It is an arithmetic number, because the mean of its divisors is an integer number (10933583289).

Almost surely, 2^21867166577 is an apocalyptic number.

It is an amenable number.

21867166577 is a deficient number, since it is larger than the sum of its proper divisors (1).

21867166577 is an equidigital number, since it uses as much as digits as its factorization.

21867166577 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5927040, while the sum is 56.

The spelling of 21867166577 in words is "twenty-one billion, eight hundred sixty-seven million, one hundred sixty-six thousand, five hundred seventy-seven".