640603746 has 24 divisors (see below), whose sum is σ = 1397295900. Its totient is φ = 212100576.

The previous prime is 640603729. The next prime is 640603763. The reversal of 640603746 is 647306046.

640603746 is a `hidden beast` number, since 6 + 4 + 0 + 603 + 7 + 46 = 666.

640603746 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (640603729) and next prime (640603763).

It can be written as a sum of positive squares in 2 ways, for example, as 442892025 + 197711721 = 21045^2 + 14061^2 .

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 640603746.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 116745 + ... + 122108.

Almost surely, 2^640603746 is an apocalyptic number.

640603746 is an abundant number, since it is smaller than the sum of its proper divisors (756692154).

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

640603746 is a wasteful number, since it uses less digits than its factorization.

640603746 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 239010 (or 239007 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 36.

The square root of 640603746 is about 25310.1510465663. The cubic root of 640603746 is about 862.0447765386.

The spelling of 640603746 in words is "six hundred forty million, six hundred three thousand, seven hundred forty-six".