18225639 has 12 divisors (see below), whose sum is σ = 26379600. Its totient is φ = 12125664.

The previous prime is 18225611. The next prime is 18225653. The reversal of 18225639 is 93652281.

18225639 is a `hidden beast` number, since 18 + 2 + 2 + 5 + 639 = 666.

It is not a de Polignac number, because 18225639 - 2¹⁹ = 17701351 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18225239) 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 11 ways as a sum of consecutive naturals, for example, 3342 + ... + 6900.

It is an arithmetic number, because the mean of its divisors is an integer number (2198300).

Almost surely, 2^18225639 is an apocalyptic number.

18225639 is a deficient number, since it is larger than the sum of its proper divisors (8153961).

18225639 is a wasteful number, since it uses less digits than its factorization.

18225639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4134 (or 4131 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 18225639 is about 4269.1496811426. The cubic root of 18225639 is about 263.1646720367.

The spelling of 18225639 in words is "eighteen million, two hundred twenty-five thousand, six hundred thirty-nine".