1221455216444 has 24 divisors (see below), whose sum is σ = 2173228243200. Its totient is φ = 600594462000.

The previous prime is 1221455216441. The next prime is 1221455216453. The reversal of 1221455216444 is 4446125541221.

It is a super-3 number, since 3×1221455216444³ (a number of 37 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221455216441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7620614 + ... + 7779245.

It is an arithmetic number, because the mean of its divisors is an integer number (90551176800).

Almost surely, 2^{1221455216444} is an apocalyptic number.

It is an amenable number.

1221455216444 is a deficient number, since it is larger than the sum of its proper divisors (951773026756).

1221455216444 is a wasteful number, since it uses less digits than its factorization.

1221455216444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15400193 (or 15400191 counting only the distinct ones).

The product of its digits is 307200, while the sum is 41.

The spelling of 1221455216444 in words is "one trillion, two hundred twenty-one billion, four hundred fifty-five million, two hundred sixteen thousand, four hundred forty-four".