640442160 has 160 divisors (see below), whose sum is σ = 2214144000. Its totient is φ = 170152704.

The previous prime is 640442147. The next prime is 640442167. The reversal of 640442160 is 61244046.

640442160 is a `hidden beast` number, since 64 + 0 + 442 + 160 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (640442167) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1034331 + ... + 1034949.

It is an arithmetic number, because the mean of its divisors is an integer number (13838400).

Almost surely, 2^640442160 is an apocalyptic number.

640442160 is a gapful number since it is divisible by the number (60) 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 640442160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1107072000).

640442160 is an abundant number, since it is smaller than the sum of its proper divisors (1573701840).

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

640442160 is a wasteful number, since it uses less digits than its factorization.

640442160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1120 (or 1108 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 27.

The square root of 640442160 is about 25306.9587268008. The cubic root of 640442160 is about 861.9722896690.

The spelling of 640442160 in words is "six hundred forty million, four hundred forty-two thousand, one hundred sixty".