16818638 has 4 divisors (see below), whose sum is σ = 25227960. Its totient is φ = 8409318.

The previous prime is 16818631. The next prime is 16818643. The reversal of 16818638 is 83681861.

It is a semiprime because it is the product of two primes.

It is a junction number, because it is equal to n+sod(n) for n = 16818595 and 16818604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16818631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4204658 + ... + 4204661.

It is an arithmetic number, because the mean of its divisors is an integer number (6306990).

Almost surely, 2^16818638 is an apocalyptic number.

16818638 is a deficient number, since it is larger than the sum of its proper divisors (8409322).

16818638 is an equidigital number, since it uses as much as digits as its factorization.

16818638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8409321.

The product of its digits is 55296, while the sum is 41.

The square root of 16818638 is about 4101.0532793418. The cubic root of 16818638 is about 256.2105100360.

The spelling of 16818638 in words is "sixteen million, eight hundred eighteen thousand, six hundred thirty-eight".