123405540131129 has 2 divisors, whose sum is σ = 123405540131130. Its totient is φ = 123405540131128.

The previous prime is 123405540131119. The next prime is 123405540131131. The reversal of 123405540131129 is 921131045504321.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 122918287269904 + 487252861225 = 11086852^2 + 698035^2 .

It is a cyclic number.

It is not a de Polignac number, because 123405540131129 - 2²⁴ = 123405523353913 is a prime.

It is a Sophie Germain prime.

Together with 123405540131131, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (123405540131119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61702770065564 + 61702770065565.

It is an arithmetic number, because the mean of its divisors is an integer number (61702770065565).

Almost surely, 2^{123405540131129} is an apocalyptic number.

It is an amenable number.

123405540131129 is a deficient number, since it is larger than the sum of its proper divisors (1).

123405540131129 is an equidigital number, since it uses as much as digits as its factorization.

123405540131129 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 129600, while the sum is 41.

The spelling of 123405540131129 in words is "one hundred twenty-three trillion, four hundred five billion, five hundred forty million, one hundred thirty-one thousand, one hundred twenty-nine".