640248464 has 20 divisors (see below), whose sum is σ = 1257955200. Its totient is φ = 315614880.

The previous prime is 640248421. The next prime is 640248551. The reversal of 640248464 is 464842046.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 280664 + ... + 282935.

It is an arithmetic number, because the mean of its divisors is an integer number (62897760).

Almost surely, 2^640248464 is an apocalyptic number.

It is an amenable number.

640248464 is a deficient number, since it is larger than the sum of its proper divisors (617706736).

640248464 is a wasteful number, since it uses less digits than its factorization.

640248464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 563678 (or 563672 counting only the distinct ones).

The product of its (nonzero) digits is 147456, while the sum is 38.

The square root of 640248464 is about 25303.1315058038. The cubic root of 640248464 is about 861.8853823052.

The spelling of 640248464 in words is "six hundred forty million, two hundred forty-eight thousand, four hundred sixty-four".