20117808 has 150 divisors (see below), whose sum is σ = 62881764. Its totient is φ = 6205248.

The previous prime is 20117777. The next prime is 20117821. The reversal of 20117808 is 80871102.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 467835 + ... + 467877.

Almost surely, 2^20117808 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 20117808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31440882).

20117808 is an abundant number, since it is smaller than the sum of its proper divisors (42763956).

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

20117808 is a wasteful number, since it uses less digits than its factorization.

20117808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101 (or 67 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 27.

The square root of 20117808 is about 4485.2879506226. The cubic root of 20117808 is about 271.9736854589.

The spelling of 20117808 in words is "twenty million, one hundred seventeen thousand, eight hundred eight".