18871808 has 80 divisors (see below), whose sum is σ = 41247360. Its totient is φ = 8601600.

The previous prime is 18871789. The next prime is 18871841. The reversal of 18871808 is 80817881.

It is a super-2 number, since 2×18871808² = 712290274377728, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 460268 + ... + 460308.

It is an arithmetic number, because the mean of its divisors is an integer number (515592).

Almost surely, 2^18871808 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18871808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20623680).

18871808 is an abundant number, since it is smaller than the sum of its proper divisors (22375552).

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

18871808 is an equidigital number, since it uses as much as digits as its factorization.

18871808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119 (or 103 counting only the distinct ones).

The product of its (nonzero) digits is 28672, while the sum is 41.

The square root of 18871808 is about 4344.1694257936. The cubic root of 18871808 is about 266.2386912842.

The spelling of 18871808 in words is "eighteen million, eight hundred seventy-one thousand, eight hundred eight".