18439019 has 4 divisors (see below), whose sum is σ = 18741360. Its totient is φ = 18136680.

The previous prime is 18439009. The next prime is 18439039. The reversal of 18439019 is 91093481.

18439019 = 222² + 223² + ... + 404².

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 91093481 = 113 ⋅806137.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18439019 is a prime.

It is a super-2 number, since 2×18439019² = 679994843364722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18439019.

It is not an unprimeable number, because it can be changed into a prime (18439009) 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, 151079 + ... + 151200.

It is an arithmetic number, because the mean of its divisors is an integer number (4685340).

Almost surely, 2^18439019 is an apocalyptic number.

18439019 is a deficient number, since it is larger than the sum of its proper divisors (302341).

18439019 is an equidigital number, since it uses as much as digits as its factorization.

18439019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 302340.

The product of its (nonzero) digits is 7776, while the sum is 35.

The square root of 18439019 is about 4294.0678848849. The cubic root of 18439019 is about 264.1877060778.

The spelling of 18439019 in words is "eighteen million, four hundred thirty-nine thousand, nineteen".