20313111209 has 2 divisors, whose sum is σ = 20313111210. Its totient is φ = 20313111208.

The previous prime is 20313111199. The next prime is 20313111211. The reversal of 20313111209 is 90211131302.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13881552400 + 6431558809 = 117820^2 + 80197^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20313111209 is a prime.

Together with 20313111211, 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 (20313111229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10156555604 + 10156555605.

It is an arithmetic number, because the mean of its divisors is an integer number (10156555605).

Almost surely, 2^20313111209 is an apocalyptic number.

It is an amenable number.

20313111209 is a deficient number, since it is larger than the sum of its proper divisors (1).

20313111209 is an equidigital number, since it uses as much as digits as its factorization.

20313111209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 324, while the sum is 23.

The spelling of 20313111209 in words is "twenty billion, three hundred thirteen million, one hundred eleven thousand, two hundred nine".