18017840 has 20 divisors (see below), whose sum is σ = 41891664. Its totient is φ = 7207104.

The previous prime is 18017821. The next prime is 18017843. The reversal of 18017840 is 4871081.

It is a tau number, because it is divible by the number of its divisors (20).

It is a Smith number, since the sum of its digits (29) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (18017843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 112532 + ... + 112691.

Almost surely, 2^18017840 is an apocalyptic number.

18017840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18017840 is an abundant number, since it is smaller than the sum of its proper divisors (23873824).

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

18017840 is a wasteful number, since it uses less digits than its factorization.

18017840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 225236 (or 225230 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 29.

The square root of 18017840 is about 4244.7426305961. The cubic root of 18017840 is about 262.1606923632.

The spelling of 18017840 in words is "eighteen million, seventeen thousand, eight hundred forty".