217021252 has 48 divisors (see below), whose sum is σ = 463978368. Its totient is φ = 86699520.

The previous prime is 217021237. The next prime is 217021253. The reversal of 217021252 is 252120712.

It is not an unprimeable number, because it can be changed into a prime (217021253) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 48802 + ... + 53062.

It is an arithmetic number, because the mean of its divisors is an integer number (9666216).

Almost surely, 2^217021252 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 217021252, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (231989184).

217021252 is an abundant number, since it is smaller than the sum of its proper divisors (246957116).

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

217021252 is a wasteful number, since it uses less digits than its factorization.

217021252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4396 (or 4394 counting only the distinct ones).

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 217021252 is about 14731.6411848782. The cubic root of 217021252 is about 600.9441173286.

Adding to 217021252 its reverse (252120712), we get a palindrome (469141964).

The spelling of 217021252 in words is "two hundred seventeen million, twenty-one thousand, two hundred fifty-two".