215291 has 8 divisors (see below), whose sum is σ = 226800. Its totient is φ = 204160.

The previous prime is 215279. The next prime is 215297. The reversal of 215291 is 192512.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-215291 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (215297) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2375 + ... + 2463.

It is an arithmetic number, because the mean of its divisors is an integer number (28350).

2²¹⁵²⁹¹ is an apocalyptic number.

215291 is a deficient number, since it is larger than the sum of its proper divisors (11509).

215291 is an equidigital number, since it uses as much as digits as its factorization.

215291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 189.

The product of its digits is 180, while the sum is 20.

The square root of 215291 is about 463.9946120377. The cubic root of 215291 is about 59.9342798926.

It can be divided in two parts, 21 and 5291, that multiplied together give a palindrome (111111).

The spelling of 215291 in words is "two hundred fifteen thousand, two hundred ninety-one".