18363899 has 4 divisors (see below), whose sum is σ = 19330440. Its totient is φ = 17397360.

The previous prime is 18363889. The next prime is 18363911. The reversal of 18363899 is 99836381.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99836381 = 1439 ⋅69379.

It is a cyclic number.

It is not a de Polignac number, because 18363899 - 2⁴ = 18363883 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18363869) 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, 483242 + ... + 483279.

It is an arithmetic number, because the mean of its divisors is an integer number (4832610).

Almost surely, 2^18363899 is an apocalyptic number.

18363899 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

18363899 is a deficient number, since it is larger than the sum of its proper divisors (966541).

18363899 is an equidigital number, since it uses as much as digits as its factorization.

18363899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 966540.

The product of its digits is 279936, while the sum is 47.

The square root of 18363899 is about 4285.3120073106. The cubic root of 18363899 is about 263.8284535599.

The spelling of 18363899 in words is "eighteen million, three hundred sixty-three thousand, eight hundred ninety-nine".