1221455216443 has 64 divisors (see below), whose sum is σ = 1608600913920. Its totient is φ = 900948787200.

The previous prime is 1221455216441. The next prime is 1221455216453. The reversal of 1221455216443 is 3446125541221.

It is not a de Polignac number, because 1221455216443 - 2¹ = 1221455216441 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1221455216396 and 1221455216405.

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

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 90868603 + ... + 90882043.

It is an arithmetic number, because the mean of its divisors is an integer number (25134389280).

Almost surely, 2^{1221455216443} is an apocalyptic number.

1221455216443 is a deficient number, since it is larger than the sum of its proper divisors (387145697477).

1221455216443 is an equidigital number, since it uses as much as digits as its factorization.

1221455216443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13625 (or 13579 counting only the distinct ones).

The product of its digits is 230400, while the sum is 40.

The spelling of 1221455216443 in words is "one trillion, two hundred twenty-one billion, four hundred fifty-five million, two hundred sixteen thousand, four hundred forty-three".