640985465641 has 16 divisors (see below), whose sum is σ = 685508898240. Its totient is φ = 597578342400.

The previous prime is 640985465597. The next prime is 640985465741. The reversal of 640985465641 is 146564589046.

It is a cyclic number.

It is not a de Polignac number, because 640985465641 - 2¹³ = 640985457449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640985465041) 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 15 ways as a sum of consecutive naturals, for example, 92841 + ... + 1136041.

It is an arithmetic number, because the mean of its divisors is an integer number (42844306140).

Almost surely, 2^640985465641 is an apocalyptic number.

It is an amenable number.

640985465641 is a deficient number, since it is larger than the sum of its proper divisors (44523432599).

640985465641 is a wasteful number, since it uses less digits than its factorization.

640985465641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1043736.

The product of its (nonzero) digits is 24883200, while the sum is 58.

The spelling of 640985465641 in words is "six hundred forty billion, nine hundred eighty-five million, four hundred sixty-five thousand, six hundred forty-one".