18065988 has 36 divisors (see below), whose sum is σ = 46081308. Its totient is φ = 5967360.

The previous prime is 18065981. The next prime is 18066007. The reversal of 18065988 is 88956081.

It can be written as a sum of positive squares in 2 ways, for example, as 2762244 + 15303744 = 1662^2 + 3912^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×18065988² = 652759844832288, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18065981) 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, 1848 + ... + 6288.

Almost surely, 2^18065988 is an apocalyptic number.

18065988 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

18065988 is an abundant number, since it is smaller than the sum of its proper divisors (28015320).

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

18065988 is a wasteful number, since it uses less digits than its factorization.

18065988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4564 (or 4559 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 45.

The square root of 18065988 is about 4250.4103331326. The cubic root of 18065988 is about 262.3940034633.

The spelling of 18065988 in words is "eighteen million, sixty-five thousand, nine hundred eighty-eight".