221530313 has 2 divisors, whose sum is σ = 221530314. Its totient is φ = 221530312.

The previous prime is 221530307. The next prime is 221530321. The reversal of 221530313 is 313035122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 110923024 + 110607289 = 10532^2 + 10517^2 .

It is a cyclic number.

It is not a de Polignac number, because 221530313 - 2²⁴ = 204753097 is a prime.

It is not a weakly prime, because it can be changed into another prime (221530363) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110765156 + 110765157.

It is an arithmetic number, because the mean of its divisors is an integer number (110765157).

Almost surely, 2^221530313 is an apocalyptic number.

It is an amenable number.

221530313 is a deficient number, since it is larger than the sum of its proper divisors (1).

221530313 is an equidigital number, since it uses as much as digits as its factorization.

221530313 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 540, while the sum is 20.

The square root of 221530313 is about 14883.8944164489. The cubic root of 221530313 is about 605.0775694544.

Adding to 221530313 its reverse (313035122), we get a palindrome (534565435).

The spelling of 221530313 in words is "two hundred twenty-one million, five hundred thirty thousand, three hundred thirteen".