640643635620334 has 8 divisors (see below), whose sum is σ = 960965636362488. Its totient is φ = 320321756832840.

The previous prime is 640643635620323. The next prime is 640643635620349. The reversal of 640643635620334 is 433026536346046.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15973812 + ... + 39197575.

It is an arithmetic number, because the mean of its divisors is an integer number (120120704545311).

Almost surely, 2^{640643635620334} is an apocalyptic number.

640643635620334 is a deficient number, since it is larger than the sum of its proper divisors (320322000742154).

640643635620334 is a wasteful number, since it uses less digits than its factorization.

640643635620334 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60977330.

The product of its (nonzero) digits is 67184640, while the sum is 55.

The spelling of 640643635620334 in words is "six hundred forty trillion, six hundred forty-three billion, six hundred thirty-five million, six hundred twenty thousand, three hundred thirty-four".