644777544822 has 8 divisors (see below), whose sum is σ = 1289555089656. Its totient is φ = 214925848272.

The previous prime is 644777544799. The next prime is 644777544839. The reversal of 644777544822 is 228445777446.

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

644777544822 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53731462063 + ... + 53731462074.

It is an arithmetic number, because the mean of its divisors is an integer number (161194386207).

Almost surely, 2^644777544822 is an apocalyptic number.

644777544822 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

644777544822 is a wasteful number, since it uses less digits than its factorization.

644777544822 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107462924142.

The product of its digits is 84295680, while the sum is 60.

The spelling of 644777544822 in words is "six hundred forty-four billion, seven hundred seventy-seven million, five hundred forty-four thousand, eight hundred twenty-two".