1221644725444 has 96 divisors (see below), whose sum is σ = 2584665974016. Its totient is φ = 497728903680.

The previous prime is 1221644725373. The next prime is 1221644725451. The reversal of 1221644725444 is 4445274461221.

It is a super-3 number, since 3×1221644725444³ (a number of 37 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a junction number, because it is equal to n+sod(n) for n = 1221644725394 and 1221644725403.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10588114 + ... + 10702870.

It is an arithmetic number, because the mean of its divisors is an integer number (26923603896).

Almost surely, 2^{1221644725444} is an apocalyptic number.

It is an amenable number.

1221644725444 is an abundant number, since it is smaller than the sum of its proper divisors (1363021248572).

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

1221644725444 is a wasteful number, since it uses less digits than its factorization.

1221644725444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115325 (or 115323 counting only the distinct ones).

The product of its digits is 1720320, while the sum is 46.

The spelling of 1221644725444 in words is "one trillion, two hundred twenty-one billion, six hundred forty-four million, seven hundred twenty-five thousand, four hundred forty-four".