85516763921 has 4 divisors (see below), whose sum is σ = 85524593892. Its totient is φ = 85508933952.

The previous prime is 85516763881. The next prime is 85516763987. The reversal of 85516763921 is 12936761558.

It is a happy number.

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 58908629521 + 26608134400 = 242711^2 + 163120^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-85516763921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (85516765921) 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, 3898580 + ... + 3920453.

It is an arithmetic number, because the mean of its divisors is an integer number (21381148473).

Almost surely, 2^85516763921 is an apocalyptic number.

It is an amenable number.

85516763921 is a deficient number, since it is larger than the sum of its proper divisors (7829971).

85516763921 is a wasteful number, since it uses less digits than its factorization.

85516763921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7829970.

The product of its digits is 2721600, while the sum is 53.

The spelling of 85516763921 in words is "eighty-five billion, five hundred sixteen million, seven hundred sixty-three thousand, nine hundred twenty-one".