20218660 has 96 divisors (see below), whose sum is σ = 55802880. Its totient is φ = 5961600.

The previous prime is 20218637. The next prime is 20218669. The reversal of 20218660 is 6681202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20218669) 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, 28915 + ... + 29605.

It is an arithmetic number, because the mean of its divisors is an integer number (581280).

Almost surely, 2^20218660 is an apocalyptic number.

20218660 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 20218660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27901440).

20218660 is an abundant number, since it is smaller than the sum of its proper divisors (35584220).

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

20218660 is a wasteful number, since it uses less digits than its factorization.

20218660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 737 (or 735 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 20218660 is about 4496.5164294151. The cubic root of 20218660 is about 272.4274025950.

Adding to 20218660 its reverse (6681202), we get a palindrome (26899862).

The spelling of 20218660 in words is "twenty million, two hundred eighteen thousand, six hundred sixty".