640680440298 has 16 divisors (see below), whose sum is σ = 1281716166720. Its totient is φ = 213500932416.

The previous prime is 640680440293. The next prime is 640680440299. The reversal of 640680440298 is 892044086046.

It is a self number, because there is not a number n which added to its sum of digits gives 640680440298.

It is not an unprimeable number, because it can be changed into a prime (640680440293) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14780143 + ... + 14823426.

It is an arithmetic number, because the mean of its divisors is an integer number (80107260420).

Almost surely, 2^640680440298 is an apocalyptic number.

640680440298 is an abundant number, since it is smaller than the sum of its proper divisors (641035726422).

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

640680440298 is a wasteful number, since it uses less digits than its factorization.

640680440298 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29607181.

The product of its (nonzero) digits is 2654208, while the sum is 51.

The spelling of 640680440298 in words is "six hundred forty billion, six hundred eighty million, four hundred forty thousand, two hundred ninety-eight".