123400243 has 4 divisors (see below), whose sum is σ = 127380928. Its totient is φ = 119419560.

The previous prime is 123400213. The next prime is 123400247. The reversal of 123400243 is 342004321.

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 123400243 - 2¹⁷ = 123269171 is a prime.

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 123400243.

It is not an unprimeable number, because it can be changed into a prime (123400247) 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, 1990296 + ... + 1990357.

It is an arithmetic number, because the mean of its divisors is an integer number (31845232).

Almost surely, 2^123400243 is an apocalyptic number.

123400243 is a deficient number, since it is larger than the sum of its proper divisors (3980685).

123400243 is an equidigital number, since it uses as much as digits as its factorization.

123400243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3980684.

The product of its (nonzero) digits is 576, while the sum is 19.

The square root of 123400243 is about 11108.5661991096. The cubic root of 123400243 is about 497.8578259544.

Adding to 123400243 its reverse (342004321), we get a palindrome (465404564).

The spelling of 123400243 in words is "one hundred twenty-three million, four hundred thousand, two hundred forty-three".