85640808961 has 4 divisors (see below), whose sum is σ = 85644450900. Its totient is φ = 85637167024.

The previous prime is 85640808941. The next prime is 85640808973. The reversal of 85640808961 is 16980804658.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 22398115600 + 63242693361 = 149660^2 + 251481^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-85640808961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (85640808941) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1785466 + ... + 1832803.

It is an arithmetic number, because the mean of its divisors is an integer number (21411112725).

Almost surely, 2^85640808961 is an apocalyptic number.

It is an amenable number.

85640808961 is a deficient number, since it is larger than the sum of its proper divisors (3641939).

85640808961 is a wasteful number, since it uses less digits than its factorization.

85640808961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3641938.

The product of its (nonzero) digits is 3317760, while the sum is 55.

The spelling of 85640808961 in words is "eighty-five billion, six hundred forty million, eight hundred eight thousand, nine hundred sixty-one".