21597710669 has 2 divisors, whose sum is σ = 21597710670. Its totient is φ = 21597710668.

The previous prime is 21597710593. The next prime is 21597710681. The reversal of 21597710669 is 96601779512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15131460100 + 6466250569 = 123010^2 + 80413^2 .

It is a cyclic number.

It is not a de Polignac number, because 21597710669 - 2¹⁶ = 21597645133 is a prime.

It is a super-2 number, since 2×21597710669² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21597710669.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21597710969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10798855334 + 10798855335.

It is an arithmetic number, because the mean of its divisors is an integer number (10798855335).

Almost surely, 2^21597710669 is an apocalyptic number.

It is an amenable number.

21597710669 is a deficient number, since it is larger than the sum of its proper divisors (1).

21597710669 is an equidigital number, since it uses as much as digits as its factorization.

21597710669 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1428840, while the sum is 53.

The spelling of 21597710669 in words is "twenty-one billion, five hundred ninety-seven million, seven hundred ten thousand, six hundred sixty-nine".