18818538 has 8 divisors (see below), whose sum is σ = 37637088. Its totient is φ = 6272844.

The previous prime is 18818521. The next prime is 18818539. The reversal of 18818538 is 83581881.

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

18818538 is an admirable number.

It is a self number, because there is not a number n which added to its sum of digits gives 18818538.

It is not an unprimeable number, because it can be changed into a prime (18818539) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1568206 + ... + 1568217.

It is an arithmetic number, because the mean of its divisors is an integer number (4704636).

Almost surely, 2^18818538 is an apocalyptic number.

18818538 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18818538 is a wasteful number, since it uses less digits than its factorization.

18818538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3136428.

The product of its digits is 61440, while the sum is 42.

The square root of 18818538 is about 4338.0338864513. The cubic root of 18818538 is about 265.9879486503.

The spelling of 18818538 in words is "eighteen million, eight hundred eighteen thousand, five hundred thirty-eight".