21164599599953 has 2 divisors, whose sum is σ = 21164599599954. Its totient is φ = 21164599599952.

The previous prime is 21164599599937. The next prime is 21164599599991. The reversal of 21164599599953 is 35999599546112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12537179660944 + 8627419939009 = 3540788^2 + 2937247^2 .

It is a cyclic number.

It is not a de Polignac number, because 21164599599953 - 2⁴ = 21164599599937 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21164599589953) 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 as a sum of consecutive naturals, namely, 10582299799976 + 10582299799977.

It is an arithmetic number, because the mean of its divisors is an integer number (10582299799977).

Almost surely, 2^{21164599599953} is an apocalyptic number.

It is an amenable number.

21164599599953 is a deficient number, since it is larger than the sum of its proper divisors (1).

21164599599953 is an equidigital number, since it uses as much as digits as its factorization.

21164599599953 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1062882000, while the sum is 77.

The spelling of 21164599599953 in words is "twenty-one trillion, one hundred sixty-four billion, five hundred ninety-nine million, five hundred ninety-nine thousand, nine hundred fifty-three".