642871944 has 192 divisors, whose sum is σ = 2110795200. Its totient is φ = 179712000.

The previous prime is 642871921. The next prime is 642871961. The reversal of 642871944 is 449178246.

It is a self number, because there is not a number n which added to its sum of digits gives 642871944.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 400744 + ... + 402344.

It is an arithmetic number, because the mean of its divisors is an integer number (10993725).

Almost surely, 2^642871944 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 642871944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1055397600).

642871944 is an abundant number, since it is smaller than the sum of its proper divisors (1467923256).

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

642871944 is a wasteful number, since it uses less digits than its factorization.

642871944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1653 (or 1630 counting only the distinct ones).

The product of its digits is 387072, while the sum is 45.

The square root of 642871944 is about 25354.9195226489. The cubic root of 642871944 is about 863.0609976010.

The spelling of 642871944 in words is "six hundred forty-two million, eight hundred seventy-one thousand, nine hundred forty-four".