215613 has 6 divisors (see below), whose sum is σ = 311454. Its totient is φ = 143736.

The previous prime is 215587. The next prime is 215617. The reversal of 215613 is 316512.

It can be written as a sum of positive squares in only one way, i.e., 205209 + 10404 = 453^2 + 102^2 .

It is not a de Polignac number, because 215613 - 2¹⁰ = 214589 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215617) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11970 + ... + 11987.

It is an arithmetic number, because the mean of its divisors is an integer number (51909).

2²¹⁵⁶¹³ is an apocalyptic number.

It is an amenable number.

215613 is a deficient number, since it is larger than the sum of its proper divisors (95841).

215613 is a wasteful number, since it uses less digits than its factorization.

215613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23963 (or 23960 counting only the distinct ones).

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

The square root of 215613 is about 464.3414691797. The cubic root of 215613 is about 59.9641452449.

It can be divided in two parts, 215 and 613, that added together give a palindrome (828).

The spelling of 215613 in words is "two hundred fifteen thousand, six hundred thirteen".