85364564821 has 2 divisors, whose sum is σ = 85364564822. Its totient is φ = 85364564820.

The previous prime is 85364564819. The next prime is 85364564863. The reversal of 85364564821 is 12846546358.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 85315983921 + 48580900 = 292089^2 + 6970^2 .

It is a cyclic number.

It is not a de Polignac number, because 85364564821 - 2¹ = 85364564819 is a prime.

Together with 85364564819, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85364564801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42682282410 + 42682282411.

It is an arithmetic number, because the mean of its divisors is an integer number (42682282411).

Almost surely, 2^85364564821 is an apocalyptic number.

It is an amenable number.

85364564821 is a deficient number, since it is larger than the sum of its proper divisors (1).

85364564821 is an equidigital number, since it uses as much as digits as its factorization.

85364564821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5529600, while the sum is 52.

The spelling of 85364564821 in words is "eighty-five billion, three hundred sixty-four million, five hundred sixty-four thousand, eight hundred twenty-one".