221053236661 has 2 divisors, whose sum is σ = 221053236662. Its totient is φ = 221053236660.

The previous prime is 221053236541. The next prime is 221053236667. The reversal of 221053236661 is 166632350122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 134537838436 + 86515398225 = 366794^2 + 294135^2 .

It is a cyclic number.

It is not a de Polignac number, because 221053236661 - 2⁷ = 221053236533 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221053236661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221053236667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110526618330 + 110526618331.

It is an arithmetic number, because the mean of its divisors is an integer number (110526618331).

Almost surely, 2^221053236661 is an apocalyptic number.

It is an amenable number.

221053236661 is a deficient number, since it is larger than the sum of its proper divisors (1).

221053236661 is an equidigital number, since it uses as much as digits as its factorization.

221053236661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 77760, while the sum is 37.

Adding to 221053236661 its reverse (166632350122), we get a palindrome (387685586783).

The spelling of 221053236661 in words is "two hundred twenty-one billion, fifty-three million, two hundred thirty-six thousand, six hundred sixty-one".