221253121 has 2 divisors, whose sum is σ = 221253122. Its totient is φ = 221253120.

The previous prime is 221253089. The next prime is 221253139. The reversal of 221253121 is 121352122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 183982096 + 37271025 = 13564^2 + 6105^2 .

It is a cyclic number.

It is not a de Polignac number, because 221253121 - 2⁵ = 221253089 is a prime.

It is not a weakly prime, because it can be changed into another prime (221253191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110626560 + 110626561.

It is an arithmetic number, because the mean of its divisors is an integer number (110626561).

Almost surely, 2^221253121 is an apocalyptic number.

It is an amenable number.

221253121 is a deficient number, since it is larger than the sum of its proper divisors (1).

221253121 is an equidigital number, since it uses as much as digits as its factorization.

221253121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 240, while the sum is 19.

The square root of 221253121 is about 14874.5796915409. The cubic root of 221253121 is about 604.8250943523.

Subtracting from 221253121 its reverse (121352122), we obtain a palindrome (99900999).

The spelling of 221253121 in words is "two hundred twenty-one million, two hundred fifty-three thousand, one hundred twenty-one".