123137431 has 2 divisors, whose sum is σ = 123137432. Its totient is φ = 123137430.

The previous prime is 123137429. The next prime is 123137437. The reversal of 123137431 is 134731321.

It is a weak prime.

It is an emirp because it is prime and its reverse (134731321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 123137431 - 2¹ = 123137429 is a prime.

It is a super-2 number, since 2×123137431² = 30325653826559522, which contains 22 as substring.

Together with 123137429, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 123137396 and 123137405.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123137437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61568715 + 61568716.

It is an arithmetic number, because the mean of its divisors is an integer number (61568716).

Almost surely, 2^123137431 is an apocalyptic number.

123137431 is a deficient number, since it is larger than the sum of its proper divisors (1).

123137431 is an equidigital number, since it uses as much as digits as its factorization.

123137431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1512, while the sum is 25.

The square root of 123137431 is about 11096.7306446539. The cubic root of 123137431 is about 497.5041367298.

Adding to 123137431 its reverse (134731321), we get a palindrome (257868752).

The spelling of 123137431 in words is "one hundred twenty-three million, one hundred thirty-seven thousand, four hundred thirty-one".