18409513 has 2 divisors, whose sum is σ = 18409514. Its totient is φ = 18409512.

The previous prime is 18409507. The next prime is 18409529. The reversal of 18409513 is 31590481.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13927824 + 4481689 = 3732^2 + 2117^2 .

It is a cyclic number.

It is not a de Polignac number, because 18409513 - 2⁵ = 18409481 is a prime.

It is not a weakly prime, because it can be changed into another prime (18409543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9204756 + 9204757.

It is an arithmetic number, because the mean of its divisors is an integer number (9204757).

Almost surely, 2^18409513 is an apocalyptic number.

It is an amenable number.

18409513 is a deficient number, since it is larger than the sum of its proper divisors (1).

18409513 is an equidigital number, since it uses as much as digits as its factorization.

18409513 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 18409513 is about 4290.6308393988. The cubic root of 18409513 is about 264.0467136881.

Adding to 18409513 its reverse (31590481), we get a palindrome (49999994).

The spelling of 18409513 in words is "eighteen million, four hundred nine thousand, five hundred thirteen".