217226920 has 64 divisors (see below), whose sum is σ = 508032000. Its totient is φ = 83504640.

The previous prime is 217226879. The next prime is 217226921. The reversal of 217226920 is 29622712.

217226920 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is not an unprimeable number, because it can be changed into a prime (217226921) 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, 206556 + ... + 207604.

It is an arithmetic number, because the mean of its divisors is an integer number (7938000).

Almost surely, 2^217226920 is an apocalyptic number.

217226920 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 217226920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (254016000).

217226920 is an abundant number, since it is smaller than the sum of its proper divisors (290805080).

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

217226920 is a wasteful number, since it uses less digits than its factorization.

217226920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1258 (or 1254 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 31.

The square root of 217226920 is about 14738.6200168130. The cubic root of 217226920 is about 601.1338928322.

It can be divided in two parts, 2172 and 26920, that added together give a palindrome (29092).

The spelling of 217226920 in words is "two hundred seventeen million, two hundred twenty-six thousand, nine hundred twenty".