640707657730155 has 16 divisors (see below), whose sum is σ = 1139035835964960. Its totient is φ = 341710750789344.

The previous prime is 640707657730139. The next prime is 640707657730157. The reversal of 640707657730155 is 551037756707046.

640707657730155 is a `hidden beast` number, since 6 + 4 + 0 + 7 + 0 + 7 + 6 + 577 + 3 + 0 + 1 + 55 = 666.

It is not a de Polignac number, because 640707657730155 - 2⁴ = 640707657730139 is a prime.

It is a super-2 number, since 2×640707657730155² (a number of 30 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 640707657730092 and 640707657730101.

It is not an unprimeable number, because it can be changed into a prime (640707657730157) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2372991324792 + ... + 2372991325061.

It is an arithmetic number, because the mean of its divisors is an integer number (71189739747810).

Almost surely, 2^{640707657730155} is an apocalyptic number.

640707657730155 is a deficient number, since it is larger than the sum of its proper divisors (498328178234805).

640707657730155 is a wasteful number, since it uses less digits than its factorization.

640707657730155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4745982649867 (or 4745982649861 counting only the distinct ones).

The product of its (nonzero) digits is 129654000, while the sum is 63.

The spelling of 640707657730155 in words is "six hundred forty trillion, seven hundred seven billion, six hundred fifty-seven million, seven hundred thirty thousand, one hundred fifty-five".