18399019 has 4 divisors (see below), whose sum is σ = 18415000. Its totient is φ = 18383040.

The previous prime is 18399001. The next prime is 18399023. The reversal of 18399019 is 91099381.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18399019 - 2⁹ = 18398507 is a prime.

It is a super-2 number, since 2×18399019² = 677047800324722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18399319) 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, 6117 + ... + 8614.

It is an arithmetic number, because the mean of its divisors is an integer number (4603750).

Almost surely, 2^18399019 is an apocalyptic number.

18399019 is a deficient number, since it is larger than the sum of its proper divisors (15981).

18399019 is a wasteful number, since it uses less digits than its factorization.

18399019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15980.

The product of its (nonzero) digits is 17496, while the sum is 40.

The square root of 18399019 is about 4289.4077679792. The cubic root of 18399019 is about 263.9965325149.

The spelling of 18399019 in words is "eighteen million, three hundred ninety-nine thousand, nineteen".