123391543 has 4 divisors (see below), whose sum is σ = 134608968. Its totient is φ = 112174120.

The previous prime is 123391537. The next prime is 123391561. The reversal of 123391543 is 345193321.

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 123391543 - 2⁵ = 123391511 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123391523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5608696 + ... + 5608717.

It is an arithmetic number, because the mean of its divisors is an integer number (33652242).

Almost surely, 2^123391543 is an apocalyptic number.

123391543 is a deficient number, since it is larger than the sum of its proper divisors (11217425).

123391543 is a wasteful number, since it uses less digits than its factorization.

123391543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11217424.

The product of its digits is 9720, while the sum is 31.

The square root of 123391543 is about 11108.1746025168. The cubic root of 123391543 is about 497.8461256401.

The spelling of 123391543 in words is "one hundred twenty-three million, three hundred ninety-one thousand, five hundred forty-three".