123400257 has 4 divisors (see below), whose sum is σ = 164533680. Its totient is φ = 82266836.

The previous prime is 123400247. The next prime is 123400259. The reversal of 123400257 is 752004321.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 123400257 - 2²⁰ = 122351681 is a prime.

It is not an unprimeable number, because it can be changed into a prime (123400259) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20566707 + ... + 20566712.

It is an arithmetic number, because the mean of its divisors is an integer number (41133420).

Almost surely, 2^123400257 is an apocalyptic number.

It is an amenable number.

123400257 is a deficient number, since it is larger than the sum of its proper divisors (41133423).

123400257 is an equidigital number, since it uses as much as digits as its factorization.

123400257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41133422.

The product of its (nonzero) digits is 1680, while the sum is 24.

The square root of 123400257 is about 11108.5668292539. The cubic root of 123400257 is about 497.8578447820.

Adding to 123400257 its reverse (752004321), we get a palindrome (875404578).

The spelling of 123400257 in words is "one hundred twenty-three million, four hundred thousand, two hundred fifty-seven".