851431591922 has 18 divisors (see below), whose sum is σ = 1285169711247. Its totient is φ = 423058289724.

The previous prime is 851431591909. The next prime is 851431591957. The reversal of 851431591922 is 229195134158.

It can be written as a sum of positive squares in only one way, i.e., 425715795961 + 425715795961 = 652469^2 + 652469^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=652469.

It is a super-2 number, since 2×851431591922² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 217922693 + ... + 217926599.

Almost surely, 2^851431591922 is an apocalyptic number.

851431591922 is a deficient number, since it is larger than the sum of its proper divisors (433738119325).

851431591922 is an frugal number, since it uses more digits than its factorization.

851431591922 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8150 (or 4076 counting only the distinct ones).

The product of its digits is 777600, while the sum is 50.

Multiplying 851431591922 by its sum of digits (50), we get a square (42571579596100 = 6524690²).

The spelling of 851431591922 in words is "eight hundred fifty-one billion, four hundred thirty-one million, five hundred ninety-one thousand, nine hundred twenty-two".