640000044040 has 64 divisors (see below), whose sum is σ = 1645787756160. Its totient is φ = 219418805760.

The previous prime is 640000044001. The next prime is 640000044053. The reversal of 640000044040 is 40440000046.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9304575 + ... + 9373105.

It is an arithmetic number, because the mean of its divisors is an integer number (25715433690).

Almost surely, 2^640000044040 is an apocalyptic number.

It is an amenable number.

640000044040 is an abundant number, since it is smaller than the sum of its proper divisors (1005787712120).

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

640000044040 is a wasteful number, since it uses less digits than its factorization.

640000044040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101902 (or 101898 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 22.

Adding to 640000044040 its reverse (40440000046), we get a palindrome (680440044086).

The spelling of 640000044040 in words is "six hundred forty billion, forty-four thousand, forty".