18208040 has 16 divisors (see below), whose sum is σ = 40968180. Its totient is φ = 7283200.

The previous prime is 18208013. The next prime is 18208051. The reversal of 18208040 is 4080281.

It can be written as a sum of positive squares in 2 ways, for example, as 15952036 + 2256004 = 3994^2 + 1502^2 .

It is a junction number, because it is equal to n+sod(n) for n = 18207997 and 18208015.

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 3 ways as a sum of consecutive naturals, for example, 227561 + ... + 227640.

Almost surely, 2^18208040 is an apocalyptic number.

18208040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18208040 is an abundant number, since it is smaller than the sum of its proper divisors (22760140).

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

18208040 is a wasteful number, since it uses less digits than its factorization.

18208040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 455212 (or 455208 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 23.

The square root of 18208040 is about 4267.0880000300. The cubic root of 18208040 is about 263.0799392674.

The spelling of 18208040 in words is "eighteen million, two hundred eight thousand, forty".