642177851904 has 120 divisors (see below), whose sum is σ = 1853684040780. Its totient is φ = 214022873088.

The previous prime is 642177851857. The next prime is 642177851921. The reversal of 642177851904 is 409158771246.

642177851904 is a `hidden beast` number, since 6 + 42 + 17 + 78 + 519 + 0 + 4 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 642177849600 + 2304 = 801360^2 + 48^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 49709254 + ... + 49722170.

Almost surely, 2^642177851904 is an apocalyptic number.

642177851904 is a gapful number since it is divisible by the number (64) 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 642177851904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (926842020390).

642177851904 is an abundant number, since it is smaller than the sum of its proper divisors (1211506188876).

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

642177851904 is a wasteful number, since it uses less digits than its factorization.

642177851904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23730 (or 23711 counting only the distinct ones).

The product of its (nonzero) digits is 3386880, while the sum is 54.

The spelling of 642177851904 in words is "six hundred forty-two billion, one hundred seventy-seven million, eight hundred fifty-one thousand, nine hundred four".