18099816 has 48 divisors (see below), whose sum is σ = 52640640. Its totient is φ = 5171040.

The previous prime is 18099811. The next prime is 18099821. The reversal of 18099816 is 61899081.

It is an interprime number because it is at equal distance from previous prime (18099811) and next prime (18099821).

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (18099811) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6520 + ... + 8871.

It is an arithmetic number, because the mean of its divisors is an integer number (1096680).

Almost surely, 2^18099816 is an apocalyptic number.

It is an amenable number.

18099816 is an abundant number, since it is smaller than the sum of its proper divisors (34540824).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18099816 is a wasteful number, since it uses less digits than its factorization.

18099816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15414 (or 15403 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 42.

The square root of 18099816 is about 4254.3878525588. The cubic root of 18099816 is about 262.5576762154.

It can be divided in two parts, 18099 and 816, that added together give a triangular number (18915 = T₁₉₄).

The spelling of 18099816 in words is "eighteen million, ninety-nine thousand, eight hundred sixteen".