18120724 has 6 divisors (see below), whose sum is σ = 31711274. Its totient is φ = 9060360.

The previous prime is 18120719. The next prime is 18120727. The reversal of 18120724 is 42702181.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 12830724 + 5290000 = 3582^2 + 2300^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18120727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2265087 + ... + 2265094.

Almost surely, 2^18120724 is an apocalyptic number.

It is an amenable number.

18120724 is a deficient number, since it is larger than the sum of its proper divisors (13590550).

18120724 is a wasteful number, since it uses less digits than its factorization.

18120724 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4530185 (or 4530183 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 25.

The square root of 18120724 is about 4256.8443711275. The cubic root of 18120724 is about 262.6587351340.

The spelling of 18120724 in words is "eighteen million, one hundred twenty thousand, seven hundred twenty-four".