217871892 has 72 divisors (see below), whose sum is σ = 632393216. Its totient is φ = 61953984.

The previous prime is 217871891. The next prime is 217871897. The reversal of 217871892 is 298178712.

It is a super-2 number, since 2×217871892² = 94936322647319328, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217871891) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 54258 + ... + 58134.

Almost surely, 2^217871892 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 217871892, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (316196608).

217871892 is an abundant number, since it is smaller than the sum of its proper divisors (414521324).

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

217871892 is a wasteful number, since it uses less digits than its factorization.

217871892 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4117 (or 4112 counting only the distinct ones).

The product of its digits is 112896, while the sum is 45.

The square root of 217871892 is about 14760.4841384014. The cubic root of 217871892 is about 601.7282504709.

The spelling of 217871892 in words is "two hundred seventeen million, eight hundred seventy-one thousand, eight hundred ninety-two".