18049840 has 40 divisors (see below), whose sum is σ = 42997248. Its totient is φ = 7042560.

The previous prime is 18049831. The next prime is 18049853. The reversal of 18049840 is 4894081.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 18049796 and 18049805.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 529 + ... + 6031.

Almost surely, 2^18049840 is an apocalyptic number.

18049840 is a gapful number since it is divisible by the number (10) 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 18049840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21498624).

18049840 is an abundant number, since it is smaller than the sum of its proper divisors (24947408).

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

18049840 is a wasteful number, since it uses less digits than its factorization.

18049840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5557 (or 5551 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 34.

The square root of 18049840 is about 4248.5103271617. The cubic root of 18049840 is about 262.3158012373.

The spelling of 18049840 in words is "eighteen million, forty-nine thousand, eight hundred forty".