18240724 has 6 divisors (see below), whose sum is σ = 31921274. Its totient is φ = 9120360.

The previous prime is 18240713. The next prime is 18240743. The reversal of 18240724 is 42704281.

It can be written as a sum of positive squares in only one way, i.e., 15350724 + 2890000 = 3918^2 + 1700^2 .

It is a junction number, because it is equal to n+sod(n) for n = 18240692 and 18240701.

It is a congruent number.

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 as a sum of consecutive naturals, namely, 2280087 + ... + 2280094.

Almost surely, 2^18240724 is an apocalyptic number.

It is an amenable number.

18240724 is a deficient number, since it is larger than the sum of its proper divisors (13680550).

18240724 is a wasteful number, since it uses less digits than its factorization.

18240724 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4560185 (or 4560183 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 28.

The square root of 18240724 is about 4270.9160609874. The cubic root of 18240724 is about 263.2372574081.

The spelling of 18240724 in words is "eighteen million, two hundred forty thousand, seven hundred twenty-four".