640458855 has 12 divisors (see below), whose sum is σ = 1110128760. Its totient is φ = 341578032.

The previous prime is 640458811. The next prime is 640458887. The reversal of 640458855 is 558854046.

640458855 is a `hidden beast` number, since 64 + 0 + 4 + 588 + 5 + 5 = 666.

It is not a de Polignac number, because 640458855 - 2¹⁷ = 640327783 is a prime.

It is a super-2 number, since 2×640458855² = 820375089895822050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45), and also a Moran number because the ratio is a prime number: 14232419 = 640458855 / (6 + 4 + 0 + 4 + 5 + 8 + 8 + 5 + 5).

It is a self number, because there is not a number n which added to its sum of digits gives 640458855.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7116165 + ... + 7116254.

It is an arithmetic number, because the mean of its divisors is an integer number (92510730).

Almost surely, 2^640458855 is an apocalyptic number.

640458855 is a deficient number, since it is larger than the sum of its proper divisors (469669905).

640458855 is a wasteful number, since it uses less digits than its factorization.

640458855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14232430 (or 14232427 counting only the distinct ones).

The product of its (nonzero) digits is 768000, while the sum is 45.

The square root of 640458855 is about 25307.2885746379. The cubic root of 640458855 is about 861.9797795477.

It can be divided in two parts, 64045 and 8855, that added together give a square (72900 = 270²).

The spelling of 640458855 in words is "six hundred forty million, four hundred fifty-eight thousand, eight hundred fifty-five".