640635323055 has 128 divisors (see below), whose sum is σ = 1296282408960. Its totient is φ = 262945751040.

The previous prime is 640635323047. The next prime is 640635323087. The reversal of 640635323055 is 550323536046.

640635323055 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 640635323055 - 2³ = 640635323047 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 640635322998 and 640635323016.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 14122851 + ... + 14168139.

It is an arithmetic number, because the mean of its divisors is an integer number (10127206320).

Almost surely, 2^640635323055 is an apocalyptic number.

640635323055 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

640635323055 is an abundant number, since it is smaller than the sum of its proper divisors (655647085905).

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

640635323055 is a wasteful number, since it uses less digits than its factorization.

640635323055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45601.

The product of its (nonzero) digits is 972000, while the sum is 42.

The spelling of 640635323055 in words is "six hundred forty billion, six hundred thirty-five million, three hundred twenty-three thousand, fifty-five".