640360633644 has 36 divisors (see below), whose sum is σ = 1618774925040. Its totient is φ = 213442263840.

The previous prime is 640360633613. The next prime is 640360633667. The reversal of 640360633644 is 446336063046.

It is a happy number.

640360633644 is a `hidden beast` number, since 6 + 4 + 0 + 3 + 6 + 0 + 633 + 6 + 4 + 4 = 666.

640360633644 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×640360633644² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 640360633644.

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, 235114 + ... + 1155854.

It is an arithmetic number, because the mean of its divisors is an integer number (44965970140).

Almost surely, 2^640360633644 is an apocalyptic number.

It is an amenable number.

640360633644 is an abundant number, since it is smaller than the sum of its proper divisors (978414291396).

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

640360633644 is a wasteful number, since it uses less digits than its factorization.

640360633644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 940070 (or 940065 counting only the distinct ones).

The product of its (nonzero) digits is 2239488, while the sum is 45.

The spelling of 640360633644 in words is "six hundred forty billion, three hundred sixty million, six hundred thirty-three thousand, six hundred forty-four".