216867191 has 8 divisors (see below), whose sum is σ = 224627520. Its totient is φ = 209125728.

The previous prime is 216867187. The next prime is 216867193. The reversal of 216867191 is 191768612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 216867191 - 2² = 216867187 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216867193) 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, 21170 + ... + 29696.

It is an arithmetic number, because the mean of its divisors is an integer number (28078440).

Almost surely, 2^216867191 is an apocalyptic number.

216867191 is a deficient number, since it is larger than the sum of its proper divisors (7760329).

216867191 is an equidigital number, since it uses as much as digits as its factorization.

216867191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9433.

The product of its digits is 36288, while the sum is 41.

The square root of 216867191 is about 14726.4113415319. The cubic root of 216867191 is about 600.8018824597.

The spelling of 216867191 in words is "two hundred sixteen million, eight hundred sixty-seven thousand, one hundred ninety-one".