123648509 has 4 divisors (see below), whose sum is σ = 125213760. Its totient is φ = 122083260.

The previous prime is 123648479. The next prime is 123648541. The reversal of 123648509 is 905846321.

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: 905846321 = 37 ⋅24482333.

It is a cyclic number.

It is not a de Polignac number, because 123648509 - 2²⁰ = 122599933 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123644509) 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, 782507 + ... + 782664.

It is an arithmetic number, because the mean of its divisors is an integer number (31303440).

Almost surely, 2^123648509 is an apocalyptic number.

It is an amenable number.

123648509 is a deficient number, since it is larger than the sum of its proper divisors (1565251).

123648509 is an equidigital number, since it uses as much as digits as its factorization.

123648509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1565250.

The product of its (nonzero) digits is 51840, while the sum is 38.

The square root of 123648509 is about 11119.7351137516. The cubic root of 123648509 is about 498.1914783861.

The spelling of 123648509 in words is "one hundred twenty-three million, six hundred forty-eight thousand, five hundred nine".