123423137561 has 2 divisors, whose sum is σ = 123423137562. Its totient is φ = 123423137560.

The previous prime is 123423137557. The next prime is 123423137587. The reversal of 123423137561 is 165731324321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 94098630025 + 29324507536 = 306755^2 + 171244^2 .

It is a cyclic number.

It is not a de Polignac number, because 123423137561 - 2² = 123423137557 is a prime.

It is not a weakly prime, because it can be changed into another prime (123423130561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61711568780 + 61711568781.

It is an arithmetic number, because the mean of its divisors is an integer number (61711568781).

Almost surely, 2^123423137561 is an apocalyptic number.

It is an amenable number.

123423137561 is a deficient number, since it is larger than the sum of its proper divisors (1).

123423137561 is an equidigital number, since it uses as much as digits as its factorization.

123423137561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 90720, while the sum is 38.

The spelling of 123423137561 in words is "one hundred twenty-three billion, four hundred twenty-three million, one hundred thirty-seven thousand, five hundred sixty-one".