21590968169 has 2 divisors, whose sum is σ = 21590968170. Its totient is φ = 21590968168.

The previous prime is 21590968159. The next prime is 21590968187. The reversal of 21590968169 is 96186909512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20793640000 + 797328169 = 144200^2 + 28237^2 .

It is a cyclic number.

It is not a de Polignac number, because 21590968169 - 2⁸ = 21590967913 is a prime.

It is a super-2 number, since 2×21590968169² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21590968159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10795484084 + 10795484085.

It is an arithmetic number, because the mean of its divisors is an integer number (10795484085).

Almost surely, 2^21590968169 is an apocalyptic number.

It is an amenable number.

21590968169 is a deficient number, since it is larger than the sum of its proper divisors (1).

21590968169 is an equidigital number, since it uses as much as digits as its factorization.

21590968169 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2099520, while the sum is 56.

The spelling of 21590968169 in words is "twenty-one billion, five hundred ninety million, nine hundred sixty-eight thousand, one hundred sixty-nine".