215191 has 2 divisors, whose sum is σ = 215192. Its totient is φ = 215190.

The previous prime is 215183. The next prime is 215197. The reversal of 215191 is 191512.

215191 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 215191 - 2³ = 215183 is a prime.

215191 is a lucky number.

It is equal to p₁₉₂₂₅ and since 215191 and 19225 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (215197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107595 + 107596.

It is an arithmetic number, because the mean of its divisors is an integer number (107596).

2²¹⁵¹⁹¹ is an apocalyptic number.

215191 is a deficient number, since it is larger than the sum of its proper divisors (1).

215191 is an equidigital number, since it uses as much as digits as its factorization.

215191 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 90, while the sum is 19.

The square root of 215191 is about 463.8868396495. The cubic root of 215191 is about 59.9249988789.

It can be divided in two parts, 215 and 191, that added together give a triangular number (406 = T₂₈).

The spelling of 215191 in words is "two hundred fifteen thousand, one hundred ninety-one".