215231 has 4 divisors (see below), whose sum is σ = 217464. Its totient is φ = 213000.

The previous prime is 215197. The next prime is 215239. The reversal of 215231 is 132512.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-215231 is a prime.

It is a super-2 number, since 2×215231² = 92648766722, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215239) 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 3 ways as a sum of consecutive naturals, for example, 965 + ... + 1166.

It is an arithmetic number, because the mean of its divisors is an integer number (54366).

2²¹⁵²³¹ is an apocalyptic number.

215231 is a deficient number, since it is larger than the sum of its proper divisors (2233).

215231 is a wasteful number, since it uses less digits than its factorization.

215231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2232.

The product of its digits is 60, while the sum is 14.

The square root of 215231 is about 463.9299516091. The cubic root of 215231 is about 59.9287116293.

Adding to 215231 its reverse (132512), we get a palindrome (347743).

The spelling of 215231 in words is "two hundred fifteen thousand, two hundred thirty-one".