1221331297 has 2 divisors, whose sum is σ = 1221331298. Its totient is φ = 1221331296.

The previous prime is 1221331291. The next prime is 1221331301. The reversal of 1221331297 is 7921331221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1051315776 + 170015521 = 32424^2 + 13039^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221331297 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221331291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610665648 + 610665649.

It is an arithmetic number, because the mean of its divisors is an integer number (610665649).

Almost surely, 2^1221331297 is an apocalyptic number.

It is an amenable number.

1221331297 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221331297 is an equidigital number, since it uses as much as digits as its factorization.

1221331297 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4536, while the sum is 31.

The square root of 1221331297 is about 34947.5506580933. The cubic root of 1221331297 is about 1068.9182583738.

The spelling of 1221331297 in words is "one billion, two hundred twenty-one million, three hundred thirty-one thousand, two hundred ninety-seven".