18810399 has 16 divisors (see below), whose sum is σ = 26506880. Its totient is φ = 11832480.

The previous prime is 18810383. The next prime is 18810401. The reversal of 18810399 is 99301881.

It is a happy number.

It is not a de Polignac number, because 18810399 - 2⁴ = 18810383 is a prime.

It is a super-2 number, since 2×18810399² = 707662221078402, 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 (18810499) 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 15 ways as a sum of consecutive naturals, for example, 18369 + ... + 19365.

It is an arithmetic number, because the mean of its divisors is an integer number (1656680).

Almost surely, 2^18810399 is an apocalyptic number.

18810399 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

18810399 is a deficient number, since it is larger than the sum of its proper divisors (7696481).

18810399 is a wasteful number, since it uses less digits than its factorization.

18810399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1350.

The product of its (nonzero) digits is 15552, while the sum is 39.

The square root of 18810399 is about 4337.0956872082. The cubic root of 18810399 is about 265.9495966081.

The spelling of 18810399 in words is "eighteen million, eight hundred ten thousand, three hundred ninety-nine".