640250855791 has 2 divisors, whose sum is σ = 640250855792. Its totient is φ = 640250855790.

The previous prime is 640250855779. The next prime is 640250855861. The reversal of 640250855791 is 197558052046.

It is a happy number.

640250855791 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 640250855791 - 2¹⁷ = 640250724719 is a prime.

It is a super-2 number, since 2×640250855791² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640250805791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320125427895 + 320125427896.

It is an arithmetic number, because the mean of its divisors is an integer number (320125427896).

Almost surely, 2^640250855791 is an apocalyptic number.

640250855791 is a deficient number, since it is larger than the sum of its proper divisors (1).

640250855791 is an equidigital number, since it uses as much as digits as its factorization.

640250855791 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3024000, while the sum is 52.

The spelling of 640250855791 in words is "six hundred forty billion, two hundred fifty million, eight hundred fifty-five thousand, seven hundred ninety-one".