640807002 has 96 divisors (see below), whose sum is σ = 1590091776. Its totient is φ = 184615200.

The previous prime is 640806989. The next prime is 640807003. The reversal of 640807002 is 200708046.

It is a super-2 number, since 2×640807002² = 821267227624456008, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (640807003) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1015227 + ... + 1015857.

It is an arithmetic number, because the mean of its divisors is an integer number (16563456).

Almost surely, 2^640807002 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640807002, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (795045888).

640807002 is an abundant number, since it is smaller than the sum of its proper divisors (949284774).

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

640807002 is a wasteful number, since it uses less digits than its factorization.

640807002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 896 (or 893 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 640807002 is about 25314.1660340608. The cubic root of 640807002 is about 862.1359391053.

The spelling of 640807002 in words is "six hundred forty million, eight hundred seven thousand, two".