18228939 has 8 divisors (see below), whose sum is σ = 24351120. Its totient is φ = 12129696.

The previous prime is 18228937. The next prime is 18228941. The reversal of 18228939 is 93982281.

It is an interprime number because it is at equal distance from previous prime (18228937) and next prime (18228941).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18228939 - 2¹ = 18228937 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18228939.

It is not an unprimeable number, because it can be changed into a prime (18228937) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3784 + ... + 7125.

It is an arithmetic number, because the mean of its divisors is an integer number (3043890).

Almost surely, 2^18228939 is an apocalyptic number.

18228939 is a deficient number, since it is larger than the sum of its proper divisors (6122181).

18228939 is a wasteful number, since it uses less digits than its factorization.

18228939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11469.

The product of its digits is 62208, while the sum is 42.

The square root of 18228939 is about 4269.5361574766. The cubic root of 18228939 is about 263.1805542600.

The spelling of 18228939 in words is "eighteen million, two hundred twenty-eight thousand, nine hundred thirty-nine".