123189431 has 2 divisors, whose sum is σ = 123189432. Its totient is φ = 123189430.

The previous prime is 123189427. The next prime is 123189433. The reversal of 123189431 is 134981321.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 123189431 - 2² = 123189427 is a prime.

It is a super-2 number, since 2×123189431² = 30351271820207522, which contains 22 as substring.

Together with 123189433, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123189433) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61594715 + 61594716.

It is an arithmetic number, because the mean of its divisors is an integer number (61594716).

Almost surely, 2^123189431 is an apocalyptic number.

123189431 is a deficient number, since it is larger than the sum of its proper divisors (1).

123189431 is an equidigital number, since it uses as much as digits as its factorization.

123189431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5184, while the sum is 32.

The square root of 123189431 is about 11099.0734297958. The cubic root of 123189431 is about 497.5741576113.

The spelling of 123189431 in words is "one hundred twenty-three million, one hundred eighty-nine thousand, four hundred thirty-one".