561664216656444 has 48 divisors (see below), whose sum is σ = 1460109685095936. Its totient is φ = 166579973990400.

The previous prime is 561664216656421. The next prime is 561664216656581. The reversal of 561664216656444 is 444656612466165.

It is a Harshad number since it is a multiple of its sum of digits (66).

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, 45266291077 + ... + 45266303484.

It is an arithmetic number, because the mean of its divisors is an integer number (30418951772832).

Almost surely, 2^{561664216656444} is an apocalyptic number.

It is an amenable number.

561664216656444 is an abundant number, since it is smaller than the sum of its proper divisors (898445468439492).

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

561664216656444 is a wasteful number, since it uses less digits than its factorization.

561664216656444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90532594626 (or 90532594624 counting only the distinct ones).

The product of its digits is 597196800, while the sum is 66.

The spelling of 561664216656444 in words is "five hundred sixty-one trillion, six hundred sixty-four billion, two hundred sixteen million, six hundred fifty-six thousand, four hundred forty-four".