1321232312009 has 2 divisors, whose sum is σ = 1321232312010. Its totient is φ = 1321232312008.

The previous prime is 1321232311999. The next prime is 1321232312017. The reversal of 1321232312009 is 9002132321231.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1314404925625 + 6827386384 = 1146475^2 + 82628^2 .

It is a cyclic number.

It is not a de Polignac number, because 1321232312009 - 2²⁸ = 1320963876553 is a prime.

It is not a weakly prime, because it can be changed into another prime (1321232312089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660616156004 + 660616156005.

It is an arithmetic number, because the mean of its divisors is an integer number (660616156005).

Almost surely, 2^{1321232312009} is an apocalyptic number.

It is an amenable number.

1321232312009 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321232312009 is an equidigital number, since it uses as much as digits as its factorization.

1321232312009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 29.

The spelling of 1321232312009 in words is "one trillion, three hundred twenty-one billion, two hundred thirty-two million, three hundred twelve thousand, nine".