215316 has 18 divisors (see below), whose sum is σ = 544362. Its totient is φ = 71760.

The previous prime is 215309. The next prime is 215317. The reversal of 215316 is 613512.

Added to its reverse (613512) it gives a triangular number (828828 = T₁₂₈₇).

215316 = T₂₂₈ + T₂₂₉ + ... + T₂₃₅.

It can be written as a sum of positive squares in only one way, i.e., 125316 + 90000 = 354^2 + 300^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215317) by changing a digit.

215316 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2955 + ... + 3026.

2²¹⁵³¹⁶ is an apocalyptic number.

It is an amenable number.

215316 is an abundant number, since it is smaller than the sum of its proper divisors (329046).

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

215316 is a wasteful number, since it uses less digits than its factorization.

215316 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5991 (or 5986 counting only the distinct ones).

The product of its digits is 180, while the sum is 18.

The square root of 215316 is about 464.0215512236. The cubic root of 215316 is about 59.9365996970.

Adding to 215316 its product of digits (180), we get a triangular number (215496 = T₆₅₆).

Adding to 215316 its reverse (613512), we get a palindrome (828828).

The spelling of 215316 in words is "two hundred fifteen thousand, three hundred sixteen".