640200731648 has 44 divisors (see below), whose sum is σ = 1280482017600. Its totient is φ = 319923843072.

The previous prime is 640200731647. The next prime is 640200731657. The reversal of 640200731648 is 846137002046.

It is not an unprimeable number, because it can be changed into a prime (640200731647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1695278 + ... + 2038226.

Almost surely, 2^640200731648 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640200731648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (640241008800).

640200731648 is an abundant number, since it is smaller than the sum of its proper divisors (640281285952).

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

640200731648 is a wasteful number, since it uses less digits than its factorization.

640200731648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 344792 (or 344774 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 41.

The spelling of 640200731648 in words is "six hundred forty billion, two hundred million, seven hundred thirty-one thousand, six hundred forty-eight".