644867768446 has 32 divisors (see below), whose sum is σ = 1092868899840. Its totient is φ = 282844413600.

The previous prime is 644867768353. The next prime is 644867768497.

644867768446 is nontrivially palindromic in base 10.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4318581 + ... + 4465408.

It is an arithmetic number, because the mean of its divisors is an integer number (34152153120).

Almost surely, 2^644867768446 is an apocalyptic number.

644867768446 is a deficient number, since it is larger than the sum of its proper divisors (448001131394).

644867768446 is a wasteful number, since it uses less digits than its factorization.

644867768446 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8784120.

The product of its digits is 1040449536, while the sum is 70.

The spelling of 644867768446 in words is "six hundred forty-four billion, eight hundred sixty-seven million, seven hundred sixty-eight thousand, four hundred forty-six".