123138431 has 8 divisors (see below), whose sum is σ = 132704880. Its totient is φ = 113585472.

The previous prime is 123138427. The next prime is 123138467. The reversal of 123138431 is 134831321.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 123138431 - 2² = 123138427 is a prime.

It is a super-2 number, since 2×123138431² = 30326146378283522, which 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 123138431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123138401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23675 + ... + 28403.

It is an arithmetic number, because the mean of its divisors is an integer number (16588110).

Almost surely, 2^123138431 is an apocalyptic number.

123138431 is a deficient number, since it is larger than the sum of its proper divisors (9566449).

123138431 is a wasteful number, since it uses less digits than its factorization.

123138431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6745.

The product of its digits is 1728, while the sum is 26.

The square root of 123138431 is about 11096.7757028787. The cubic root of 123138431 is about 497.5054834711.

Adding to 123138431 its reverse (134831321), we get a palindrome (257969752).

The spelling of 123138431 in words is "one hundred twenty-three million, one hundred thirty-eight thousand, four hundred thirty-one".