18045640 has 64 divisors (see below), whose sum is σ = 42476400. Its totient is φ = 6893568.

The previous prime is 18045637. The next prime is 18045647. The reversal of 18045640 is 4654081.

It can be written as a sum of positive squares in 8 ways, for example, as 9647236 + 8398404 = 3106^2 + 2898^2 .

It is a junction number, because it is equal to n+sod(n) for n = 18045599 and 18045608.

It is not an unprimeable number, because it can be changed into a prime (18045647) 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 15 ways as a sum of consecutive naturals, for example, 131652 + ... + 131788.

Almost surely, 2^18045640 is an apocalyptic number.

18045640 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 18045640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21238200).

18045640 is an abundant number, since it is smaller than the sum of its proper divisors (24430760).

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

18045640 is a wasteful number, since it uses less digits than its factorization.

18045640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 274 (or 270 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 28.

The square root of 18045640 is about 4248.0160075028. The cubic root of 18045640 is about 262.2954536547.

The spelling of 18045640 in words is "eighteen million, forty-five thousand, six hundred forty".