217921116 has 48 divisors (see below), whose sum is σ = 582011136. Its totient is φ = 62168064.

The previous prime is 217921091. The next prime is 217921141. The reversal of 217921116 is 611129712.

It is an interprime number because it is at equal distance from previous prime (217921091) and next prime (217921141).

It is a super-2 number, since 2×217921116² = 94979225597370912, which contains 22 as substring.

It is a congruent number.

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, 67900 + ... + 71036.

It is an arithmetic number, because the mean of its divisors is an integer number (12125232).

Almost surely, 2^217921116 is an apocalyptic number.

It is an amenable number.

217921116 is an abundant number, since it is smaller than the sum of its proper divisors (364090020).

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

217921116 is a wasteful number, since it uses less digits than its factorization.

217921116 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3978 (or 3976 counting only the distinct ones).

The product of its digits is 1512, while the sum is 30.

The square root of 217921116 is about 14762.1514692134. The cubic root of 217921116 is about 601.7735634003.

The spelling of 217921116 in words is "two hundred seventeen million, nine hundred twenty-one thousand, one hundred sixteen".