79569902821 has 2 divisors, whose sum is σ = 79569902822. Its totient is φ = 79569902820.

The previous prime is 79569902809. The next prime is 79569902827. The reversal of 79569902821 is 12820996597.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 52463902500 + 27106000321 = 229050^2 + 164639^2 .

It is a cyclic number.

It is not a de Polignac number, because 79569902821 - 2³³ = 70979968229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79569902827) 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, 39784951410 + 39784951411.

It is an arithmetic number, because the mean of its divisors is an integer number (39784951411).

Almost surely, 2^79569902821 is an apocalyptic number.

It is an amenable number.

79569902821 is a deficient number, since it is larger than the sum of its proper divisors (1).

79569902821 is an equidigital number, since it uses as much as digits as its factorization.

79569902821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4898880, while the sum is 58.

The spelling of 79569902821 in words is "seventy-nine billion, five hundred sixty-nine million, nine hundred two thousand, eight hundred twenty-one".