21867050017 has 2 divisors, whose sum is σ = 21867050018. Its totient is φ = 21867050016.

The previous prime is 21867049993. The next prime is 21867050039. The reversal of 21867050017 is 71005076812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14915492641 + 6951557376 = 122129^2 + 83376^2 .

It is a cyclic number.

It is not a de Polignac number, because 21867050017 - 2⁷ = 21867049889 is a prime.

It is not a weakly prime, because it can be changed into another prime (21867050047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10933525008 + 10933525009.

It is an arithmetic number, because the mean of its divisors is an integer number (10933525009).

Almost surely, 2^21867050017 is an apocalyptic number.

It is an amenable number.

21867050017 is a deficient number, since it is larger than the sum of its proper divisors (1).

21867050017 is an equidigital number, since it uses as much as digits as its factorization.

21867050017 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23520, while the sum is 37.

The spelling of 21867050017 in words is "twenty-one billion, eight hundred sixty-seven million, fifty thousand, seventeen".