18099072 has 64 divisors (see below), whose sum is σ = 53427600. Its totient is φ = 6031872.

The previous prime is 18099061. The next prime is 18099131. The reversal of 18099072 is 27099081.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×18099072² = 655152814522368, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 838 + ... + 6074.

Almost surely, 2^18099072 is an apocalyptic number.

18099072 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18099072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26713800).

18099072 is an abundant number, since it is smaller than the sum of its proper divisors (35328528).

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

18099072 is an equidigital number, since it uses as much as digits as its factorization.

18099072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5260 (or 5242 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 18099072 is about 4254.3004125238. The cubic root of 18099072 is about 262.5540786542.

Subtracting 18099072 from its reverse (27099081), we obtain a palindrome (9000009).

The spelling of 18099072 in words is "eighteen million, ninety-nine thousand, seventy-two".