640031643161656 has 32 divisors (see below), whose sum is σ = 1204330579488000. Its totient is φ = 318876879725280.

The previous prime is 640031643161653. The next prime is 640031643161693. The reversal of 640031643161656 is 656161346130046.

It is a super-3 number, since 3×640031643161656³ (a number of 45 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640031643161653) 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, 85545745 + ... + 92726143.

It is an arithmetic number, because the mean of its divisors is an integer number (37635330609000).

Almost surely, 2^{640031643161656} is an apocalyptic number.

It is an amenable number.

640031643161656 is a deficient number, since it is larger than the sum of its proper divisors (564298936326344).

640031643161656 is a wasteful number, since it uses less digits than its factorization.

640031643161656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7220059 (or 7220055 counting only the distinct ones).

The product of its (nonzero) digits is 5598720, while the sum is 52.

The spelling of 640031643161656 in words is "six hundred forty trillion, thirty-one billion, six hundred forty-three million, one hundred sixty-one thousand, six hundred fifty-six".