123640115 has 4 divisors (see below), whose sum is σ = 148368144. Its totient is φ = 98912088.

The previous prime is 123640109. The next prime is 123640123. The reversal of 123640115 is 511046321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 511046321 = 16217 ⋅31513.

It is a cyclic number.

It is not a de Polignac number, because 123640115 - 2¹⁸ = 123377971 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12364007 + ... + 12364016.

It is an arithmetic number, because the mean of its divisors is an integer number (37092036).

Almost surely, 2^123640115 is an apocalyptic number.

123640115 is a deficient number, since it is larger than the sum of its proper divisors (24728029).

123640115 is an equidigital number, since it uses as much as digits as its factorization.

123640115 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24728028.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 123640115 is about 11119.3576702973. The cubic root of 123640115 is about 498.1802047257.

Adding to 123640115 its reverse (511046321), we get a palindrome (634686436).

The spelling of 123640115 in words is "one hundred twenty-three million, six hundred forty thousand, one hundred fifteen".