640307775 has 12 divisors (see below), whose sum is σ = 1058642312. Its totient is φ = 341497440.

The previous prime is 640307687. The next prime is 640307813. The reversal of 640307775 is 577703046.

640307775 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 640307775 - 2¹¹ = 640305727 is a prime.

It is a Duffinian number.

It is a congruent number.

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, 4268644 + ... + 4268793.

Almost surely, 2^640307775 is an apocalyptic number.

640307775 is a deficient number, since it is larger than the sum of its proper divisors (418334537).

640307775 is a wasteful number, since it uses less digits than its factorization.

640307775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8537450 (or 8537445 counting only the distinct ones).

The product of its (nonzero) digits is 123480, while the sum is 39.

The square root of 640307775 is about 25304.3034877469. The cubic root of 640307775 is about 861.9119957781.

The spelling of 640307775 in words is "six hundred forty million, three hundred seven thousand, seven hundred seventy-five".