123140257 has 4 divisors (see below), whose sum is σ = 125227440. Its totient is φ = 121053076.

The previous prime is 123140221. The next prime is 123140279. The reversal of 123140257 is 752041321.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 752041321 = 1511 ⋅497711.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-123140257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (123140557) 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, 1043503 + ... + 1043620.

It is an arithmetic number, because the mean of its divisors is an integer number (31306860).

Almost surely, 2^123140257 is an apocalyptic number.

It is an amenable number.

123140257 is a deficient number, since it is larger than the sum of its proper divisors (2087183).

123140257 is an equidigital number, since it uses as much as digits as its factorization.

123140257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2087182.

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 123140257 is about 11096.8579787253. The cubic root of 123140257 is about 497.5079426019.

Adding to 123140257 its reverse (752041321), we get a palindrome (875181578).

The spelling of 123140257 in words is "one hundred twenty-three million, one hundred forty thousand, two hundred fifty-seven".