221323313 has 2 divisors, whose sum is σ = 221323314. Its totient is φ = 221323312.

The previous prime is 221323309. The next prime is 221323339. The reversal of 221323313 is 313323122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 157051024 + 64272289 = 12532^2 + 8017^2 .

It is a cyclic number.

It is not a de Polignac number, because 221323313 - 2² = 221323309 is a prime.

It is not a weakly prime, because it can be changed into another prime (221323303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110661656 + 110661657.

It is an arithmetic number, because the mean of its divisors is an integer number (110661657).

Almost surely, 2^221323313 is an apocalyptic number.

It is an amenable number.

221323313 is a deficient number, since it is larger than the sum of its proper divisors (1).

221323313 is an equidigital number, since it uses as much as digits as its factorization.

221323313 is an evil number, because the sum of its binary digits is even.

The product of its digits is 648, while the sum is 20.

The square root of 221323313 is about 14876.9389660642. The cubic root of 221323313 is about 604.8890473400.

Adding to 221323313 its reverse (313323122), we get a palindrome (534646435).

The spelling of 221323313 in words is "two hundred twenty-one million, three hundred twenty-three thousand, three hundred thirteen".