18640724 has 12 divisors (see below), whose sum is σ = 32750004. Its totient is φ = 9283584.

The previous prime is 18640723. The next prime is 18640751. The reversal of 18640724 is 42704681.

It can be written as a sum of positive squares in 2 ways, for example, as 14364100 + 4276624 = 3790^2 + 2068^2 .

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18640723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8039 + ... + 10094.

It is an arithmetic number, because the mean of its divisors is an integer number (2729167).

Almost surely, 2^18640724 is an apocalyptic number.

It is an amenable number.

18640724 is a deficient number, since it is larger than the sum of its proper divisors (14109280).

18640724 is a wasteful number, since it uses less digits than its factorization.

18640724 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18394 (or 18392 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 32.

The square root of 18640724 is about 4317.4904748013. The cubic root of 18640724 is about 265.1475338442.

The spelling of 18640724 in words is "eighteen million, six hundred forty thousand, seven hundred twenty-four".