221001221211161 has 2 divisors, whose sum is σ = 221001221211162. Its totient is φ = 221001221211160.

The previous prime is 221001221211137. The next prime is 221001221211193. The reversal of 221001221211161 is 161112122100122.

221001221211161 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 135572978503561 + 85428242707600 = 11643581^2 + 9242740^2 .

It is a cyclic number.

It is not a de Polignac number, because 221001221211161 - 2²⁶ = 221001154102297 is a prime.

It is not a weakly prime, because it can be changed into another prime (221001221216161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110500610605580 + 110500610605581.

It is an arithmetic number, because the mean of its divisors is an integer number (110500610605581).

Almost surely, 2^{221001221211161} is an apocalyptic number.

It is an amenable number.

221001221211161 is a deficient number, since it is larger than the sum of its proper divisors (1).

221001221211161 is an equidigital number, since it uses as much as digits as its factorization.

221001221211161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 192, while the sum is 23.

Adding to 221001221211161 its reverse (161112122100122), we get a palindrome (382113343311283).

The spelling of 221001221211161 in words is "two hundred twenty-one trillion, one billion, two hundred twenty-one million, two hundred eleven thousand, one hundred sixty-one".