1321297921 has 2 divisors, whose sum is σ = 1321297922. Its totient is φ = 1321297920.

The previous prime is 1321297907. The next prime is 1321297927. The reversal of 1321297921 is 1297921231.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1259895025 + 61402896 = 35495^2 + 7836^2 .

It is a cyclic number.

It is not a de Polignac number, because 1321297921 - 2²³ = 1312909313 is a prime.

It is not a weakly prime, because it can be changed into another prime (1321297927) 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, 660648960 + 660648961.

It is an arithmetic number, because the mean of its divisors is an integer number (660648961).

Almost surely, 2^1321297921 is an apocalyptic number.

It is an amenable number.

1321297921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321297921 is an equidigital number, since it uses as much as digits as its factorization.

1321297921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13608, while the sum is 37.

The square root of 1321297921 is about 36349.6619103947. The cubic root of 1321297921 is about 1097.3207303664.

The spelling of 1321297921 in words is "one billion, three hundred twenty-one million, two hundred ninety-seven thousand, nine hundred twenty-one".