213115321 has 2 divisors, whose sum is σ = 213115322. Its totient is φ = 213115320.

The previous prime is 213115319. The next prime is 213115333. The reversal of 213115321 is 123511312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 167417721 + 45697600 = 12939^2 + 6760^2 .

It is a cyclic number.

It is not a de Polignac number, because 213115321 - 2¹ = 213115319 is a prime.

Together with 213115319, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (213115361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106557660 + 106557661.

It is an arithmetic number, because the mean of its divisors is an integer number (106557661).

Almost surely, 2^213115321 is an apocalyptic number.

It is an amenable number.

213115321 is a deficient number, since it is larger than the sum of its proper divisors (1).

213115321 is an equidigital number, since it uses as much as digits as its factorization.

213115321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 180, while the sum is 19.

The square root of 213115321 is about 14598.4698170733. The cubic root of 213115321 is about 597.3170215192.

Adding to 213115321 its reverse (123511312), we get a palindrome (336626633).

The spelling of 213115321 in words is "two hundred thirteen million, one hundred fifteen thousand, three hundred twenty-one".