123581279 has 4 divisors (see below), whose sum is σ = 130850784. Its totient is φ = 116311776.

The previous prime is 123581243. The next prime is 123581291. The reversal of 123581279 is 972185321.

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

It is a cyclic number.

It is not a de Polignac number, because 123581279 - 2⁸ = 123581023 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 (123581219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3634727 + ... + 3634760.

It is an arithmetic number, because the mean of its divisors is an integer number (32712696).

Almost surely, 2^123581279 is an apocalyptic number.

123581279 is a deficient number, since it is larger than the sum of its proper divisors (7269505).

123581279 is an equidigital number, since it uses as much as digits as its factorization.

123581279 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7269504.

The product of its digits is 30240, while the sum is 38.

The square root of 123581279 is about 11116.7116990592. The cubic root of 123581279 is about 498.1011700178.

The spelling of 123581279 in words is "one hundred twenty-three million, five hundred eighty-one thousand, two hundred seventy-nine".