221261641 has 2 divisors, whose sum is σ = 221261642. Its totient is φ = 221261640.

The previous prime is 221261629. The next prime is 221261687. The reversal of 221261641 is 146162122.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 129504400 + 91757241 = 11380^2 + 9579^2 .

It is a cyclic number.

It is not a de Polignac number, because 221261641 - 2⁹ = 221261129 is a prime.

It is not a weakly prime, because it can be changed into another prime (221261611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110630820 + 110630821.

It is an arithmetic number, because the mean of its divisors is an integer number (110630821).

Almost surely, 2^221261641 is an apocalyptic number.

It is an amenable number.

221261641 is a deficient number, since it is larger than the sum of its proper divisors (1).

221261641 is an equidigital number, since it uses as much as digits as its factorization.

221261641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1152, while the sum is 25.

The square root of 221261641 is about 14874.8660834308. The cubic root of 221261641 is about 604.8328577737.

The spelling of 221261641 in words is "two hundred twenty-one million, two hundred sixty-one thousand, six hundred forty-one".