644576451361 has 8 divisors (see below), whose sum is σ = 658305688320. Its totient is φ = 630905266992.

The previous prime is 644576451359. The next prime is 644576451377. The reversal of 644576451361 is 163154675446.

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 644576451361 - 2¹ = 644576451359 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 644576451299 and 644576451308.

It is not an unprimeable number, because it can be changed into a prime (644576451061) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14490705 + ... + 14535118.

It is an arithmetic number, because the mean of its divisors is an integer number (82288211040).

Almost surely, 2^644576451361 is an apocalyptic number.

It is an amenable number.

644576451361 is a deficient number, since it is larger than the sum of its proper divisors (13729236959).

644576451361 is a wasteful number, since it uses less digits than its factorization.

644576451361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29026295.

The product of its digits is 7257600, while the sum is 52.

The spelling of 644576451361 in words is "six hundred forty-four billion, five hundred seventy-six million, four hundred fifty-one thousand, three hundred sixty-one".