217913 has 4 divisors (see below), whose sum is σ = 218880. Its totient is φ = 216948.

The previous prime is 217909. The next prime is 217933. The reversal of 217913 is 319712.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 217913 - 2² = 217909 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 217913.

It is not an unprimeable number, because it can be changed into a prime (217933) 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, 56 + ... + 662.

It is an arithmetic number, because the mean of its divisors is an integer number (54720).

2²¹⁷⁹¹³ is an apocalyptic number.

It is an amenable number.

217913 is a deficient number, since it is larger than the sum of its proper divisors (967).

217913 is an equidigital number, since it uses as much as digits as its factorization.

217913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 966.

The product of its digits is 378, while the sum is 23.

The square root of 217913 is about 466.8115251362. The cubic root of 217913 is about 60.1766092723.

The spelling of 217913 in words is "two hundred seventeen thousand, nine hundred thirteen".