18481509 has 12 divisors (see below), whose sum is σ = 28100800. Its totient is φ = 11672424.

The previous prime is 18481501. The next prime is 18481511. The reversal of 18481509 is 90518481.

It is not a de Polignac number, because 18481509 - 2³ = 18481501 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18481501) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 53869 + ... + 54210.

Almost surely, 2^18481509 is an apocalyptic number.

18481509 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

18481509 is a deficient number, since it is larger than the sum of its proper divisors (9619291).

18481509 is a wasteful number, since it uses less digits than its factorization.

18481509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108104 (or 108101 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 36.

The square root of 18481509 is about 4299.0125610424. The cubic root of 18481509 is about 264.3904776077.

The spelling of 18481509 in words is "eighteen million, four hundred eighty-one thousand, five hundred nine".