20313231209 has 2 divisors, whose sum is σ = 20313231210. Its totient is φ = 20313231208.

The previous prime is 20313231203. The next prime is 20313231233. The reversal of 20313231209 is 90213231302.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19832525584 + 480705625 = 140828^2 + 21925^2 .

It is a cyclic number.

It is not a de Polignac number, because 20313231209 - 2³² = 16018263913 is a prime.

It is not a weakly prime, because it can be changed into another prime (20313231203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10156615604 + 10156615605.

It is an arithmetic number, because the mean of its divisors is an integer number (10156615605).

Almost surely, 2^20313231209 is an apocalyptic number.

It is an amenable number.

20313231209 is a deficient number, since it is larger than the sum of its proper divisors (1).

20313231209 is an equidigital number, since it uses as much as digits as its factorization.

20313231209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1944, while the sum is 26.

The spelling of 20313231209 in words is "twenty billion, three hundred thirteen million, two hundred thirty-one thousand, two hundred nine".