18419509 has 4 divisors (see below), whose sum is σ = 18440640. Its totient is φ = 18398380.

The previous prime is 18419507. The next prime is 18419519. The reversal of 18419509 is 90591481.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18419509 - 2¹ = 18419507 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 (18419503) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9199 + ... + 11020.

It is an arithmetic number, because the mean of its divisors is an integer number (4610160).

Almost surely, 2^18419509 is an apocalyptic number.

It is an amenable number.

18419509 is a deficient number, since it is larger than the sum of its proper divisors (21131).

18419509 is an equidigital number, since it uses as much as digits as its factorization.

18419509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21130.

The product of its (nonzero) digits is 12960, while the sum is 37.

The square root of 18419509 is about 4291.7955449905. The cubic root of 18419509 is about 264.0944957484.

The spelling of 18419509 in words is "eighteen million, four hundred nineteen thousand, five hundred nine".