18221606 has 8 divisors (see below), whose sum is σ = 29434944. Its totient is φ = 8409960.

The previous prime is 18221563. The next prime is 18221611. The reversal of 18221606 is 60612281.

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

It is a Harshad number since it is a multiple of its sum of digits (26), and also a Moran number because the ratio is a prime number: 700831 = 18221606 / (1 + 8 + 2 + 2 + 1 + 6 + 0 + 6).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 350390 + ... + 350441.

It is an arithmetic number, because the mean of its divisors is an integer number (3679368).

Almost surely, 2^18221606 is an apocalyptic number.

18221606 is a deficient number, since it is larger than the sum of its proper divisors (11213338).

18221606 is a wasteful number, since it uses less digits than its factorization.

18221606 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 700846.

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 18221606 is about 4268.6773127047. The cubic root of 18221606 is about 263.1452594312.

Adding to 18221606 its reverse (60612281), we get a palindrome (78833887).

The spelling of 18221606 in words is "eighteen million, two hundred twenty-one thousand, six hundred six".