216171018 has 160 divisors (see below), whose sum is σ = 594739200. Its totient is φ = 57316896.

The previous prime is 216171013. The next prime is 216171041. The reversal of 216171018 is 810171612.

216171018 is a `hidden beast` number, since 21 + 617 + 10 + 18 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 216170982 and 216171000.

It is not an unprimeable number, because it can be changed into a prime (216171013) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 1702071 + ... + 1702197.

It is an arithmetic number, because the mean of its divisors is an integer number (3717120).

Almost surely, 2^216171018 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 216171018, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (297369600).

216171018 is an abundant number, since it is smaller than the sum of its proper divisors (378568182).

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

216171018 is a wasteful number, since it uses less digits than its factorization.

216171018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246 (or 237 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 27.

The square root of 216171018 is about 14702.7554560361. The cubic root of 216171018 is about 600.1583082272.

The spelling of 216171018 in words is "two hundred sixteen million, one hundred seventy-one thousand, eighteen".