18471618 has 64 divisors (see below), whose sum is σ = 45325440. Its totient is φ = 5575680.

The previous prime is 18471601. The next prime is 18471619. The reversal of 18471618 is 81617481.

It is not an unprimeable number, because it can be changed into a prime (18471619) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 71746 + ... + 72002.

It is an arithmetic number, because the mean of its divisors is an integer number (708210).

Almost surely, 2^18471618 is an apocalyptic number.

18471618 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 18471618, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22662720).

18471618 is an abundant number, since it is smaller than the sum of its proper divisors (26853822).

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

18471618 is a wasteful number, since it uses less digits than its factorization.

18471618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 301 (or 273 counting only the distinct ones).

The product of its digits is 10752, while the sum is 36.

The square root of 18471618 is about 4297.8620266360. The cubic root of 18471618 is about 264.3433033777.

The spelling of 18471618 in words is "eighteen million, four hundred seventy-one thousand, six hundred eighteen".