18166724 has 6 divisors (see below), whose sum is σ = 31791774. Its totient is φ = 9083360.

The previous prime is 18166721. The next prime is 18166747. The reversal of 18166724 is 42766181.

It can be written as a sum of positive squares in only one way, i.e., 15856324 + 2310400 = 3982^2 + 1520^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18166721) 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 as a sum of consecutive naturals, namely, 2270837 + ... + 2270844.

It is an arithmetic number, because the mean of its divisors is an integer number (5298629).

Almost surely, 2^18166724 is an apocalyptic number.

It is an amenable number.

18166724 is a deficient number, since it is larger than the sum of its proper divisors (13625050).

18166724 is a wasteful number, since it uses less digits than its factorization.

18166724 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4541685 (or 4541683 counting only the distinct ones).

The product of its digits is 16128, while the sum is 35.

The square root of 18166724 is about 4262.2440099084. The cubic root of 18166724 is about 262.8808030170.

The spelling of 18166724 in words is "eighteen million, one hundred sixty-six thousand, seven hundred twenty-four".