18136399 has 4 divisors (see below), whose sum is σ = 19203264. Its totient is φ = 17069536.

The previous prime is 18136373. The next prime is 18136409. The reversal of 18136399 is 99363181.

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 18136399 - 2¹¹ = 18134351 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18136319) 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, 533407 + ... + 533440.

It is an arithmetic number, because the mean of its divisors is an integer number (4800816).

Almost surely, 2^18136399 is an apocalyptic number.

18136399 is a deficient number, since it is larger than the sum of its proper divisors (1066865).

18136399 is a wasteful number, since it uses less digits than its factorization.

18136399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1066864.

The product of its digits is 34992, while the sum is 40.

The square root of 18136399 is about 4258.6851257166. The cubic root of 18136399 is about 262.7344493472.

The spelling of 18136399 in words is "eighteen million, one hundred thirty-six thousand, three hundred ninety-nine".