217989312 has 56 divisors (see below), whose sum is σ = 584923392. Its totient is φ = 71635200.

The previous prime is 217989307. The next prime is 217989313. The reversal of 217989312 is 213989712.

It is not an unprimeable number, because it can be changed into a prime (217989313) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5637 + ... + 21627.

Almost surely, 2^217989312 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 217989312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (292461696).

217989312 is an abundant number, since it is smaller than the sum of its proper divisors (366934080).

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

217989312 is a wasteful number, since it uses less digits than its factorization.

217989312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16077 (or 16067 counting only the distinct ones).

The product of its digits is 54432, while the sum is 42.

The square root of 217989312 is about 14764.4611144464. The cubic root of 217989312 is about 601.8363296443.

The spelling of 217989312 in words is "two hundred seventeen million, nine hundred eighty-nine thousand, three hundred twelve".