20188140 has 96 divisors (see below), whose sum is σ = 65608704. Its totient is φ = 4542720.

The previous prime is 20188111. The next prime is 20188141. The reversal of 20188140 is 4188102.

It is a self number, because there is not a number n which added to its sum of digits gives 20188140.

It is not an unprimeable number, because it can be changed into a prime (20188141) 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, 29482 + ... + 30158.

It is an arithmetic number, because the mean of its divisors is an integer number (683424).

Almost surely, 2^20188140 is an apocalyptic number.

20188140 is a gapful number since it is divisible by the number (20) 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 20188140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32804352).

20188140 is an abundant number, since it is smaller than the sum of its proper divisors (45420564).

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

20188140 is a wasteful number, since it uses less digits than its factorization.

20188140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 767 (or 765 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 24.

The square root of 20188140 is about 4493.1214094436. The cubic root of 20188140 is about 272.2902574792.

The spelling of 20188140 in words is "twenty million, one hundred eighty-eight thousand, one hundred forty".