85640808973 has 2 divisors, whose sum is σ = 85640808974. Its totient is φ = 85640808972.

The previous prime is 85640808941. The next prime is 85640808977. The reversal of 85640808973 is 37980804658.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 83141108964 + 2499700009 = 288342^2 + 49997^2 .

It is a cyclic number.

It is not a de Polignac number, because 85640808973 - 2⁵ = 85640808941 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85640808977) 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, 42820404486 + 42820404487.

It is an arithmetic number, because the mean of its divisors is an integer number (42820404487).

Almost surely, 2^85640808973 is an apocalyptic number.

It is an amenable number.

85640808973 is a deficient number, since it is larger than the sum of its proper divisors (1).

85640808973 is an equidigital number, since it uses as much as digits as its factorization.

85640808973 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11612160, while the sum is 58.

The spelling of 85640808973 in words is "eighty-five billion, six hundred forty million, eight hundred eight thousand, nine hundred seventy-three".