1221585131321 has 2 divisors, whose sum is σ = 1221585131322. Its totient is φ = 1221585131320.

The previous prime is 1221585131309. The next prime is 1221585131323. The reversal of 1221585131321 is 1231315851221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1213222943296 + 8362188025 = 1101464^2 + 91445^2 .

It is an emirp because it is prime and its reverse (1231315851221) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221585131321 is a prime.

Together with 1221585131323, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1221585131323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610792565660 + 610792565661.

It is an arithmetic number, because the mean of its divisors is an integer number (610792565661).

Almost surely, 2^{1221585131321} is an apocalyptic number.

It is an amenable number.

1221585131321 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221585131321 is an equidigital number, since it uses as much as digits as its factorization.

1221585131321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14400, while the sum is 35.

The spelling of 1221585131321 in words is "one trillion, two hundred twenty-one billion, five hundred eighty-five million, one hundred thirty-one thousand, three hundred twenty-one".