18288509 has 2 divisors, whose sum is σ = 18288510. Its totient is φ = 18288508.

The previous prime is 18288493. The next prime is 18288511. The reversal of 18288509 is 90588281.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11580409 + 6708100 = 3403^2 + 2590^2 .

It is a cyclic number.

It is not a de Polignac number, because 18288509 - 2⁴ = 18288493 is a prime.

It is a super-2 number, since 2×18288509² = 668939122886162, which contains 22 as substring.

Together with 18288511, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18288539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9144254 + 9144255.

It is an arithmetic number, because the mean of its divisors is an integer number (9144255).

Almost surely, 2^18288509 is an apocalyptic number.

It is an amenable number.

18288509 is a deficient number, since it is larger than the sum of its proper divisors (1).

18288509 is an equidigital number, since it uses as much as digits as its factorization.

18288509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 46080, while the sum is 41.

The square root of 18288509 is about 4276.5066350936. The cubic root of 18288509 is about 263.4669234406.

The spelling of 18288509 in words is "eighteen million, two hundred eighty-eight thousand, five hundred nine".