213221317 has 4 divisors (see below), whose sum is σ = 220099456. Its totient is φ = 206343180.

The previous prime is 213221251. The next prime is 213221377. The reversal of 213221317 is 713122312.

It is a happy number.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-213221317 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213221377) 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, 3439023 + ... + 3439084.

It is an arithmetic number, because the mean of its divisors is an integer number (55024864).

Almost surely, 2^213221317 is an apocalyptic number.

It is an amenable number.

213221317 is a deficient number, since it is larger than the sum of its proper divisors (6878139).

213221317 is an equidigital number, since it uses as much as digits as its factorization.

213221317 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6878138.

The product of its digits is 504, while the sum is 22.

The square root of 213221317 is about 14602.0997462694. The cubic root of 213221317 is about 597.4160332046.

Adding to 213221317 its reverse (713122312), we get a palindrome (926343629).

The spelling of 213221317 in words is "two hundred thirteen million, two hundred twenty-one thousand, three hundred seventeen".