640463632155 has 16 divisors (see below), whose sum is σ = 1138602012960. Its totient is φ = 341580603744.

The previous prime is 640463632153. The next prime is 640463632169. The reversal of 640463632155 is 551236364046.

640463632155 is a `hidden beast` number, since 6 + 4 + 0 + 4 + 6 + 3 + 632 + 1 + 5 + 5 = 666.

It is not a de Polignac number, because 640463632155 - 2¹ = 640463632153 is a prime.

It is a super-2 number, since 2×640463632155² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 640463632155.

It is not an unprimeable number, because it can be changed into a prime (640463632153) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2372087392 + ... + 2372087661.

It is an arithmetic number, because the mean of its divisors is an integer number (71162625810).

Almost surely, 2^640463632155 is an apocalyptic number.

640463632155 is a deficient number, since it is larger than the sum of its proper divisors (498138380805).

640463632155 is a wasteful number, since it uses less digits than its factorization.

640463632155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4744175067 (or 4744175061 counting only the distinct ones).

The product of its (nonzero) digits is 1555200, while the sum is 45.

The spelling of 640463632155 in words is "six hundred forty billion, four hundred sixty-three million, six hundred thirty-two thousand, one hundred fifty-five".