20388018 has 48 divisors (see below), whose sum is σ = 48985344. Its totient is φ = 5634720.

The previous prime is 20388013. The next prime is 20388019. The reversal of 20388018 is 81088302.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (20388013) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7996 + ... + 10232.

It is an arithmetic number, because the mean of its divisors is an integer number (1020528).

Almost surely, 2^20388018 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20388018, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24492672).

20388018 is an abundant number, since it is smaller than the sum of its proper divisors (28597326).

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

20388018 is a wasteful number, since it uses less digits than its factorization.

20388018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2287 (or 2280 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 30.

The square root of 20388018 is about 4515.3092917319. The cubic root of 20388018 is about 273.1859351358.

The spelling of 20388018 in words is "twenty million, three hundred eighty-eight thousand, eighteen".