640437257784 has 32 divisors (see below), whose sum is σ = 1628230320000. Its totient is φ = 209860795872.

The previous prime is 640437257783. The next prime is 640437257809. The reversal of 640437257784 is 487752734046.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640437257783) 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, 226141684 + ... + 226144515.

It is an arithmetic number, because the mean of its divisors is an integer number (50882197500).

Almost surely, 2^640437257784 is an apocalyptic number.

It is an amenable number.

640437257784 is an abundant number, since it is smaller than the sum of its proper divisors (987793062216).

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

640437257784 is a wasteful number, since it uses less digits than its factorization.

640437257784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 452286267 (or 452286263 counting only the distinct ones).

The product of its (nonzero) digits is 31610880, while the sum is 57.

The spelling of 640437257784 in words is "six hundred forty billion, four hundred thirty-seven million, two hundred fifty-seven thousand, seven hundred eighty-four".