18220608 has 84 divisors (see below), whose sum is σ = 59700160. Its totient is φ = 5204736.

The previous prime is 18220607. The next prime is 18220619. The reversal of 18220608 is 80602281.

It is a tau number, because it is divible by the number of its divisors (84).

It is not an unprimeable number, because it can be changed into a prime (18220607) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1773 + ... + 6291.

Almost surely, 2^18220608 is an apocalyptic number.

18220608 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18220608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29850080).

18220608 is an abundant number, since it is smaller than the sum of its proper divisors (41479552).

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

18220608 is a wasteful number, since it uses less digits than its factorization.

18220608 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4544 (or 4531 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 18220608 is about 4268.5604130667. The cubic root of 18220608 is about 263.1404551755.

Adding to 18220608 its reverse (80602281), we get a palindrome (98822889).

The spelling of 18220608 in words is "eighteen million, two hundred twenty thousand, six hundred eight".