215913 has 4 divisors (see below), whose sum is σ = 287888. Its totient is φ = 143940.

The previous prime is 215909. The next prime is 215921. The reversal of 215913 is 319512.

215913 is nontrivially palindromic in base 14.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 215913 - 2² = 215909 is a prime.

It is a D-number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 215913.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 215913.

It is not an unprimeable number, because it can be changed into a prime (215953) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35983 + ... + 35988.

It is an arithmetic number, because the mean of its divisors is an integer number (71972).

2²¹⁵⁹¹³ is an apocalyptic number.

It is an amenable number.

215913 is a deficient number, since it is larger than the sum of its proper divisors (71975).

215913 is an equidigital number, since it uses as much as digits as its factorization.

215913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71974.

The product of its digits is 270, while the sum is 21.

The square root of 215913 is about 464.6643950208. The cubic root of 215913 is about 59.9919433627.

It can be divided in two parts, 215 and 913, that added together give a triangular number (1128 = T₄₇).

The spelling of 215913 in words is "two hundred fifteen thousand, nine hundred thirteen".