217321212 has 12 divisors (see below), whose sum is σ = 507082856. Its totient is φ = 72440400.

The previous prime is 217321211. The next prime is 217321213. The reversal of 217321212 is 212123712.

217321212 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (217321211) and next prime (217321213).

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217321211) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9055039 + ... + 9055062.

Almost surely, 2^217321212 is an apocalyptic number.

It is an amenable number.

217321212 is an abundant number, since it is smaller than the sum of its proper divisors (289761644).

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

217321212 is a wasteful number, since it uses less digits than its factorization.

217321212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18110108 (or 18110106 counting only the distinct ones).

The product of its digits is 336, while the sum is 21.

The square root of 217321212 is about 14741.8184767009. The cubic root of 217321212 is about 601.2208586000.

Adding to 217321212 its reverse (212123712), we get a palindrome (429444924).

The spelling of 217321212 in words is "two hundred seventeen million, three hundred twenty-one thousand, two hundred twelve".