217983972 has 48 divisors (see below), whose sum is σ = 532103040. Its totient is φ = 69455584.

The previous prime is 217983959. The next prime is 217983991. The reversal of 217983972 is 279389712.

It is an unprimeable number.

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, 145258 + ... + 146750.

It is an arithmetic number, because the mean of its divisors is an integer number (11085480).

Almost surely, 2^217983972 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 217983972, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (266051520).

217983972 is an abundant number, since it is smaller than the sum of its proper divisors (314119068).

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

217983972 is a wasteful number, since it uses less digits than its factorization.

217983972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1569 (or 1521 counting only the distinct ones).

The product of its digits is 381024, while the sum is 48.

The square root of 217983972 is about 14764.2802736876. The cubic root of 217983972 is about 601.8314152868.

The spelling of 217983972 in words is "two hundred seventeen million, nine hundred eighty-three thousand, nine hundred seventy-two".