851805420904 has 8 divisors (see below), whose sum is σ = 1597135164210. Its totient is φ = 425902710448.

The previous prime is 851805420889. The next prime is 851805420937. The reversal of 851805420904 is 409024508158.

It can be written as a sum of positive squares in only one way, i.e., 743557840804 + 108247580100 = 862298^2 + 329010^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 53237838799 + ... + 53237838814.

Almost surely, 2^851805420904 is an apocalyptic number.

It is an amenable number.

851805420904 is a deficient number, since it is larger than the sum of its proper divisors (745329743306).

851805420904 is a wasteful number, since it uses less digits than its factorization.

851805420904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106475677619 (or 106475677615 counting only the distinct ones).

The product of its (nonzero) digits is 460800, while the sum is 46.

The spelling of 851805420904 in words is "eight hundred fifty-one billion, eight hundred five million, four hundred twenty thousand, nine hundred four".