18408613 has 2 divisors, whose sum is σ = 18408614. Its totient is φ = 18408612.

The previous prime is 18408583. The next prime is 18408617. The reversal of 18408613 is 31680481.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14152644 + 4255969 = 3762^2 + 2063^2 .

It is a cyclic number.

It is not a de Polignac number, because 18408613 - 2⁵ = 18408581 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18408617) 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, 9204306 + 9204307.

It is an arithmetic number, because the mean of its divisors is an integer number (9204307).

Almost surely, 2^18408613 is an apocalyptic number.

It is an amenable number.

18408613 is a deficient number, since it is larger than the sum of its proper divisors (1).

18408613 is an equidigital number, since it uses as much as digits as its factorization.

18408613 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4608, while the sum is 31.

The square root of 18408613 is about 4290.5259584345. The cubic root of 18408613 is about 264.0424107332.

The spelling of 18408613 in words is "eighteen million, four hundred eight thousand, six hundred thirteen".