18478319 has 4 divisors (see below), whose sum is σ = 18522840. Its totient is φ = 18433800.

The previous prime is 18478309. The next prime is 18478321. The reversal of 18478319 is 91387481.

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 18478319 - 2⁸ = 18478063 is a prime.

It is a super-2 number, since 2×18478319² = 682896546131522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18478309) 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, 21632 + ... + 22469.

It is an arithmetic number, because the mean of its divisors is an integer number (4630710).

Almost surely, 2^18478319 is an apocalyptic number.

18478319 is a deficient number, since it is larger than the sum of its proper divisors (44521).

18478319 is an equidigital number, since it uses as much as digits as its factorization.

18478319 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44520.

The product of its digits is 48384, while the sum is 41.

The square root of 18478319 is about 4298.6415295998. The cubic root of 18478319 is about 264.3752650304.

The spelling of 18478319 in words is "eighteen million, four hundred seventy-eight thousand, three hundred nineteen".