1221331223291 has 2 divisors, whose sum is σ = 1221331223292. Its totient is φ = 1221331223290.

The previous prime is 1221331223207. The next prime is 1221331223317. The reversal of 1221331223291 is 1923221331221.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221331223291 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221331223201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610665611645 + 610665611646.

It is an arithmetic number, because the mean of its divisors is an integer number (610665611646).

Almost surely, 2^{1221331223291} is an apocalyptic number.

1221331223291 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221331223291 is an equidigital number, since it uses as much as digits as its factorization.

1221331223291 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7776, while the sum is 32.

The spelling of 1221331223291 in words is "one trillion, two hundred twenty-one billion, three hundred thirty-one million, two hundred twenty-three thousand, two hundred ninety-one".