640856177284 has 24 divisors (see below), whose sum is σ = 1123947984600. Its totient is φ = 319728824064.

The previous prime is 640856177263. The next prime is 640856177287. The reversal of 640856177284 is 482771658046.

It can be written as a sum of positive squares in 4 ways, for example, as 142829573184 + 498026604100 = 377928^2 + 705710^2 .

It is not an unprimeable number, because it can be changed into a prime (640856177287) 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, 3966792 + ... + 4125184.

It is an arithmetic number, because the mean of its divisors is an integer number (46831166025).

Almost surely, 2^640856177284 is an apocalyptic number.

It is an amenable number.

640856177284 is a deficient number, since it is larger than the sum of its proper divisors (483091807316).

640856177284 is a wasteful number, since it uses less digits than its factorization.

640856177284 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160599 (or 160597 counting only the distinct ones).

The product of its (nonzero) digits is 18063360, while the sum is 58.

The spelling of 640856177284 in words is "six hundred forty billion, eight hundred fifty-six million, one hundred seventy-seven thousand, two hundred eighty-four".