644660485915 has 8 divisors (see below), whose sum is σ = 773633393280. Its totient is φ = 515701181952.

The previous prime is 644660485877. The next prime is 644660485933. The reversal of 644660485915 is 519584066446.

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

It is a cyclic number.

It is not a de Polignac number, because 644660485915 - 2¹⁵ = 644660453147 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 644660485915.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 3296299 + ... + 3486388.

It is an arithmetic number, because the mean of its divisors is an integer number (96704174160).

Almost surely, 2^644660485915 is an apocalyptic number.

644660485915 is a deficient number, since it is larger than the sum of its proper divisors (128972907365).

644660485915 is a wasteful number, since it uses less digits than its factorization.

644660485915 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6801701.

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

The spelling of 644660485915 in words is "six hundred forty-four billion, six hundred sixty million, four hundred eighty-five thousand, nine hundred fifteen".