221342115661 has 2 divisors, whose sum is σ = 221342115662. Its totient is φ = 221342115660.

The previous prime is 221342115641. The next prime is 221342115763. The reversal of 221342115661 is 166511243122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 160966254436 + 60375861225 = 401206^2 + 245715^2 .

It is a cyclic number.

It is not a de Polignac number, because 221342115661 - 2⁵ = 221342115629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221342115641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110671057830 + 110671057831.

It is an arithmetic number, because the mean of its divisors is an integer number (110671057831).

Almost surely, 2^221342115661 is an apocalyptic number.

It is an amenable number.

221342115661 is a deficient number, since it is larger than the sum of its proper divisors (1).

221342115661 is an equidigital number, since it uses as much as digits as its factorization.

221342115661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17280, while the sum is 34.

Adding to 221342115661 its reverse (166511243122), we get a palindrome (387853358783).

The spelling of 221342115661 in words is "two hundred twenty-one billion, three hundred forty-two million, one hundred fifteen thousand, six hundred sixty-one".