18399679 has 4 divisors (see below), whose sum is σ = 18408384. Its totient is φ = 18390976.

The previous prime is 18399673. The next prime is 18399691. The reversal of 18399679 is 97699381.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 97699381 = 13 ⋅7515337.

It is a cyclic number.

It is not a de Polignac number, because 18399679 - 2⁷ = 18399551 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 (18399673) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1074 + ... + 6160.

It is an arithmetic number, because the mean of its divisors is an integer number (4602096).

Almost surely, 2^18399679 is an apocalyptic number.

18399679 is a deficient number, since it is larger than the sum of its proper divisors (8705).

18399679 is an equidigital number, since it uses as much as digits as its factorization.

18399679 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8704.

The product of its digits is 734832, while the sum is 52.

The square root of 18399679 is about 4289.4847009868. The cubic root of 18399679 is about 263.9996891257. Note that the first 3 decimals are identical.

The spelling of 18399679 in words is "eighteen million, three hundred ninety-nine thousand, six hundred seventy-nine".