640513248 has 24 divisors (see below), whose sum is σ = 1681347528. Its totient is φ = 213504384.

The previous prime is 640513243. The next prime is 640513249. The reversal of 640513248 is 842315046.

It is a tau number, because it is divible by the number of its divisors (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640513243) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3335911 + ... + 3336102.

It is an arithmetic number, because the mean of its divisors is an integer number (70056147).

Almost surely, 2^640513248 is an apocalyptic number.

It is an amenable number.

640513248 is an abundant number, since it is smaller than the sum of its proper divisors (1040834280).

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

640513248 is a wasteful number, since it uses less digits than its factorization.

640513248 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6672026 (or 6672018 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 33.

The square root of 640513248 is about 25308.3632027044. The cubic root of 640513248 is about 862.0041809793.

The spelling of 640513248 in words is "six hundred forty million, five hundred thirteen thousand, two hundred forty-eight".