18481913 has 2 divisors, whose sum is σ = 18481914. Its totient is φ = 18481912.

The previous prime is 18481901. The next prime is 18481919. The reversal of 18481913 is 31918481.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18003049 + 478864 = 4243^2 + 692^2 .

It is a cyclic number.

It is not a de Polignac number, because 18481913 - 2²⁰ = 17433337 is a prime.

It is a super-2 number, since 2×18481913² = 683162216279138, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (18481919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9240956 + 9240957.

It is an arithmetic number, because the mean of its divisors is an integer number (9240957).

Almost surely, 2^18481913 is an apocalyptic number.

It is an amenable number.

18481913 is a deficient number, since it is larger than the sum of its proper divisors (1).

18481913 is an equidigital number, since it uses as much as digits as its factorization.

18481913 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6912, while the sum is 35.

The square root of 18481913 is about 4299.0595483198. The cubic root of 18481913 is about 264.3924040913.

The spelling of 18481913 in words is "eighteen million, four hundred eighty-one thousand, nine hundred thirteen".