221313251 has 2 divisors, whose sum is σ = 221313252. Its totient is φ = 221313250.

The previous prime is 221313241. The next prime is 221313263. The reversal of 221313251 is 152313122.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 221313251 - 2⁶ = 221313187 is a prime.

It is not a weakly prime, because it can be changed into another prime (221313241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110656625 + 110656626.

It is an arithmetic number, because the mean of its divisors is an integer number (110656626).

Almost surely, 2^221313251 is an apocalyptic number.

221313251 is a deficient number, since it is larger than the sum of its proper divisors (1).

221313251 is an equidigital number, since it uses as much as digits as its factorization.

221313251 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 360, while the sum is 20.

The square root of 221313251 is about 14876.6007878144. The cubic root of 221313251 is about 604.8798805306.

Adding to 221313251 its reverse (152313122), we get a palindrome (373626373).

The spelling of 221313251 in words is "two hundred twenty-one million, three hundred thirteen thousand, two hundred fifty-one".