644576451376 has 80 divisors (see below), whose sum is σ = 1501321409280. Its totient is φ = 264162044160.

The previous prime is 644576451359. The next prime is 644576451377. The reversal of 644576451376 is 673154675446.

It is a self number, because there is not a number n which added to its sum of digits gives 644576451376.

It is not an unprimeable number, because it can be changed into a prime (644576451377) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3177436 + ... + 3374203.

It is an arithmetic number, because the mean of its divisors is an integer number (18766517616).

Almost surely, 2^644576451376 is an apocalyptic number.

It is an amenable number.

644576451376 is an abundant number, since it is smaller than the sum of its proper divisors (856744957904).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644576451376 is a wasteful number, since it uses less digits than its factorization.

644576451376 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6551714 (or 6551708 counting only the distinct ones).

The product of its digits is 50803200, while the sum is 58.

The spelling of 644576451376 in words is "six hundred forty-four billion, five hundred seventy-six million, four hundred fifty-one thousand, three hundred seventy-six".