123205131431 has 4 divisors (see below), whose sum is σ = 123227631912. Its totient is φ = 123182630952.

The previous prime is 123205131421. The next prime is 123205131437. The reversal of 123205131431 is 134131502321.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 123205131431 - 2¹⁰ = 123205130407 is a prime.

It is a super-2 number, since 2×123205131431² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 123205131431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123205131437) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11242025 + ... + 11252978.

It is an arithmetic number, because the mean of its divisors is an integer number (30806907978).

Almost surely, 2^123205131431 is an apocalyptic number.

123205131431 is a deficient number, since it is larger than the sum of its proper divisors (22500481).

123205131431 is an equidigital number, since it uses as much as digits as its factorization.

123205131431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22500480.

The product of its (nonzero) digits is 2160, while the sum is 26.

Adding to 123205131431 its reverse (134131502321), we get a palindrome (257336633752).

The spelling of 123205131431 in words is "one hundred twenty-three billion, two hundred five million, one hundred thirty-one thousand, four hundred thirty-one".