20872218 has 32 divisors (see below), whose sum is σ = 43228800. Its totient is φ = 6713280.

The previous prime is 20872217. The next prime is 20872219. The reversal of 20872218 is 81227802.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20872217) and next prime (20872219).

It is not an unprimeable number, because it can be changed into a prime (20872211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32763 + ... + 33393.

It is an arithmetic number, because the mean of its divisors is an integer number (1350900).

Almost surely, 2^20872218 is an apocalyptic number.

20872218 is an abundant number, since it is smaller than the sum of its proper divisors (22356582).

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

20872218 is a wasteful number, since it uses less digits than its factorization.

20872218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 822.

The product of its (nonzero) digits is 3584, while the sum is 30.

The square root of 20872218 is about 4568.6122619456. The cubic root of 20872218 is about 275.3316901306.

The spelling of 20872218 in words is "twenty million, eight hundred seventy-two thousand, two hundred eighteen".