851808061944 has 384 divisors, whose sum is σ = 2831531489280. Its totient is φ = 226020326400.

The previous prime is 851808061919. The next prime is 851808061957. The reversal of 851808061944 is 449160808158.

It is a happy number.

851808061944 is a `hidden beast` number, since 8 + 5 + 18 + 0 + 8 + 0 + 619 + 4 + 4 = 666.

It is a hoax number, since the sum of its digits (54) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 232035229 + ... + 232038899.

It is an arithmetic number, because the mean of its divisors is an integer number (7373779920).

Almost surely, 2^851808061944 is an apocalyptic number.

851808061944 is a gapful number since it is divisible by the number (84) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 851808061944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1415765744640).

851808061944 is an abundant number, since it is smaller than the sum of its proper divisors (1979723427336).

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

851808061944 is a wasteful number, since it uses less digits than its factorization.

851808061944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4291 (or 4284 counting only the distinct ones).

The product of its (nonzero) digits is 2211840, while the sum is 54.

The spelling of 851808061944 in words is "eight hundred fifty-one billion, eight hundred eight million, sixty-one thousand, nine hundred forty-four".