20311123109 has 2 divisors, whose sum is σ = 20311123110. Its totient is φ = 20311123108.

The previous prime is 20311123103. The next prime is 20311123159. The reversal of 20311123109 is 90132111302.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14701562500 + 5609560609 = 121250^2 + 74897^2 .

It is a cyclic number.

It is not a de Polignac number, because 20311123109 - 2²⁴ = 20294345893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20311123103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10155561554 + 10155561555.

It is an arithmetic number, because the mean of its divisors is an integer number (10155561555).

Almost surely, 2^20311123109 is an apocalyptic number.

It is an amenable number.

20311123109 is a deficient number, since it is larger than the sum of its proper divisors (1).

20311123109 is an equidigital number, since it uses as much as digits as its factorization.

20311123109 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 20311123109 in words is "twenty billion, three hundred eleven million, one hundred twenty-three thousand, one hundred nine".