123665513 has 4 divisors (see below), whose sum is σ = 123842628. Its totient is φ = 123488400.

The previous prime is 123665501. The next prime is 123665519. The reversal of 123665513 is 315566321.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 69672409 + 53993104 = 8347^2 + 7348^2 .

It is a cyclic number.

It is not a de Polignac number, because 123665513 - 2²⁴ = 106888297 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 123665513.

It is not an unprimeable number, because it can be changed into a prime (123665519) 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, 87506 + ... + 88907.

It is an arithmetic number, because the mean of its divisors is an integer number (30960657).

Almost surely, 2^123665513 is an apocalyptic number.

It is an amenable number.

123665513 is a deficient number, since it is larger than the sum of its proper divisors (177115).

123665513 is an equidigital number, since it uses as much as digits as its factorization.

123665513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177114.

The product of its digits is 16200, while the sum is 32.

The square root of 123665513 is about 11120.4996740254. The cubic root of 123665513 is about 498.2143142447.

The spelling of 123665513 in words is "one hundred twenty-three million, six hundred sixty-five thousand, five hundred thirteen".