640599380 has 48 divisors (see below), whose sum is σ = 1385940864. Its totient is φ = 248572800.

The previous prime is 640599371. The next prime is 640599391. The reversal of 640599380 is 83995046.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 127394 + ... + 132326.

It is an arithmetic number, because the mean of its divisors is an integer number (28873768).

Almost surely, 2^640599380 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 640599380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (692970432).

640599380 is an abundant number, since it is smaller than the sum of its proper divisors (745341484).

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

640599380 is a wasteful number, since it uses less digits than its factorization.

640599380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5136 (or 5134 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 44.

The square root of 640599380 is about 25310.0647964402. The cubic root of 640599380 is about 862.0428181278.

The spelling of 640599380 in words is "six hundred forty million, five hundred ninety-nine thousand, three hundred eighty".