18062721 has 12 divisors (see below), whose sum is σ = 27625572. Its totient is φ = 11333376.

The previous prime is 18062719. The next prime is 18062741. The reversal of 18062721 is 12726081.

18062721 is a `hidden beast` number, since 18 + 0 + 627 + 21 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 15210000 + 2852721 = 3900^2 + 1689^2 .

It is not a de Polignac number, because 18062721 - 2¹ = 18062719 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18062701) 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 in 11 ways as a sum of consecutive naturals, for example, 58876 + ... + 59181.

It is an arithmetic number, because the mean of its divisors is an integer number (2302131).

Almost surely, 2^18062721 is an apocalyptic number.

It is an amenable number.

18062721 is a deficient number, since it is larger than the sum of its proper divisors (9562851).

18062721 is a wasteful number, since it uses less digits than its factorization.

18062721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118080 (or 118077 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 27.

The square root of 18062721 is about 4250.0259999205. The cubic root of 18062721 is about 262.3781856571.

The spelling of 18062721 in words is "eighteen million, sixty-two thousand, seven hundred twenty-one".