20218170 has 64 divisors (see below), whose sum is σ = 56770560. Its totient is φ = 4511808.

The previous prime is 20218141. The next prime is 20218183. The reversal of 20218170 is 7181202.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7911 + ... + 10149.

It is an arithmetic number, because the mean of its divisors is an integer number (887040).

Almost surely, 2^20218170 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20218170, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28385280).

20218170 is an abundant number, since it is smaller than the sum of its proper divisors (36552390).

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

20218170 is a wasteful number, since it uses less digits than its factorization.

20218170 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2299.

The product of its (nonzero) digits is 224, while the sum is 21.

The square root of 20218170 is about 4496.4619424610. The cubic root of 20218170 is about 272.4252018144.

Adding to 20218170 its reverse (7181202), we get a palindrome (27399372).

The spelling of 20218170 in words is "twenty million, two hundred eighteen thousand, one hundred seventy".