123318581 has 2 divisors, whose sum is σ = 123318582. Its totient is φ = 123318580.

The previous prime is 123318563. The next prime is 123318583. The reversal of 123318581 is 185813321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 115756081 + 7562500 = 10759^2 + 2750^2 .

It is an emirp because it is prime and its reverse (185813321) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-123318581 is a prime.

It is a super-2 number, since 2×123318581² = 30414944839707122, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 123318583, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123318583) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61659290 + 61659291.

It is an arithmetic number, because the mean of its divisors is an integer number (61659291).

Almost surely, 2^123318581 is an apocalyptic number.

It is an amenable number.

123318581 is a deficient number, since it is larger than the sum of its proper divisors (1).

123318581 is an equidigital number, since it uses as much as digits as its factorization.

123318581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5760, while the sum is 32.

The square root of 123318581 is about 11104.8899589325. The cubic root of 123318581 is about 497.7479800406.

The spelling of 123318581 in words is "one hundred twenty-three million, three hundred eighteen thousand, five hundred eighty-one".