640627648 has 112 divisors (see below), whose sum is σ = 1392814080. Its totient is φ = 291456000.

The previous prime is 640627621. The next prime is 640627651. The reversal of 640627648 is 846726046.

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, 4608763 + ... + 4608901.

It is an arithmetic number, because the mean of its divisors is an integer number (12435840).

Almost surely, 2^640627648 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 640627648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (696407040).

640627648 is an abundant number, since it is smaller than the sum of its proper divisors (752186432).

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

640627648 is a wasteful number, since it uses less digits than its factorization.

640627648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 306 (or 296 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 43.

The square root of 640627648 is about 25310.6232242511. The cubic root of 640627648 is about 862.0554978507.

The spelling of 640627648 in words is "six hundred forty million, six hundred twenty-seven thousand, six hundred forty-eight".