850865794921 has 24 divisors (see below), whose sum is σ = 957770312040. Its totient is φ = 753128257536.

The previous prime is 850865794901. The next prime is 850865794949. The reversal of 850865794921 is 129497568058.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 65451547225 + 785414247696 = 255835^2 + 886236^2 .

It is a de Polignac number, because none of the positive numbers 2^k-850865794921 is a prime.

It is not an unprimeable number, because it can be changed into a prime (850865794901) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 334765 + ... + 1346773.

It is an arithmetic number, because the mean of its divisors is an integer number (39907096335).

Almost surely, 2^850865794921 is an apocalyptic number.

It is an amenable number.

850865794921 is a deficient number, since it is larger than the sum of its proper divisors (106904517119).

850865794921 is a wasteful number, since it uses less digits than its factorization.

850865794921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1012201 (or 1012182 counting only the distinct ones).

The product of its (nonzero) digits is 43545600, while the sum is 64.

The spelling of 850865794921 in words is "eight hundred fifty billion, eight hundred sixty-five million, seven hundred ninety-four thousand, nine hundred twenty-one".