221641313 has 2 divisors, whose sum is σ = 221641314. Its totient is φ = 221641312.

The previous prime is 221641309. The next prime is 221641333. The reversal of 221641313 is 313146122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 211324369 + 10316944 = 14537^2 + 3212^2 .

It is a cyclic number.

It is not a de Polignac number, because 221641313 - 2² = 221641309 is a prime.

It is not a weakly prime, because it can be changed into another prime (221641333) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110820656 + 110820657.

It is an arithmetic number, because the mean of its divisors is an integer number (110820657).

Almost surely, 2^221641313 is an apocalyptic number.

It is an amenable number.

221641313 is a deficient number, since it is larger than the sum of its proper divisors (1).

221641313 is an equidigital number, since it uses as much as digits as its factorization.

221641313 is an evil number, because the sum of its binary digits is even.

The product of its digits is 864, while the sum is 23.

The square root of 221641313 is about 14887.6228122558. The cubic root of 221641313 is about 605.1786126551.

Adding to 221641313 its reverse (313146122), we get a palindrome (534787435).

The spelling of 221641313 in words is "two hundred twenty-one million, six hundred forty-one thousand, three hundred thirteen".