18399811 has 8 divisors (see below), whose sum is σ = 18721280. Its totient is φ = 18080712.

The previous prime is 18399791. The next prime is 18399853. The reversal of 18399811 is 11899381.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18399811 - 2¹³ = 18391619 is a prime.

It is the 4290-th Hogben number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18399911) by changing a digit.

It is a nontrivial repunit in base 4289.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21946 + ... + 22768.

It is an arithmetic number, because the mean of its divisors is an integer number (2340160).

Almost surely, 2^18399811 is an apocalyptic number.

18399811 is a deficient number, since it is larger than the sum of its proper divisors (321469).

18399811 is an equidigital number, since it uses as much as digits as its factorization.

18399811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1185.

The product of its digits is 15552, while the sum is 40.

The square root of 18399811 is about 4289.5000874228. The cubic root of 18399811 is about 264.0003204389. Note that the first 3 decimals are identical.

The spelling of 18399811 in words is "eighteen million, three hundred ninety-nine thousand, eight hundred eleven".