851891004 has 36 divisors (see below), whose sum is σ = 2156959896. Its totient is φ = 283493088.

The previous prime is 851891003. The next prime is 851891023. The reversal of 851891004 is 400198158.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×851891004² = 1451436565392256032, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 851891004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (851891003) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2767 + ... + 41369.

Almost surely, 2^851891004 is an apocalyptic number.

It is an amenable number.

851891004 is an abundant number, since it is smaller than the sum of its proper divisors (1305068892).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

851891004 is a wasteful number, since it uses less digits than its factorization.

851891004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39226 (or 39221 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 36.

The square root of 851891004 is about 29187.1719082202. The cubic root of 851891004 is about 947.9701827934.

The spelling of 851891004 in words is "eight hundred fifty-one million, eight hundred ninety-one thousand, four".