211221302161 has 2 divisors, whose sum is σ = 211221302162. Its totient is φ = 211221302160.

The previous prime is 211221302113. The next prime is 211221302213. The reversal of 211221302161 is 161203122112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 142841667136 + 68379635025 = 377944^2 + 261495^2 .

It is a cyclic number.

It is not a de Polignac number, because 211221302161 - 2⁹ = 211221301649 is a prime.

It is a super-2 number, since 2×211221302161² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (211221302101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105610651080 + 105610651081.

It is an arithmetic number, because the mean of its divisors is an integer number (105610651081).

Almost surely, 2^211221302161 is an apocalyptic number.

It is an amenable number.

211221302161 is a deficient number, since it is larger than the sum of its proper divisors (1).

211221302161 is an equidigital number, since it uses as much as digits as its factorization.

211221302161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 22.

Adding to 211221302161 its reverse (161203122112), we get a palindrome (372424424273).

The spelling of 211221302161 in words is "two hundred eleven billion, two hundred twenty-one million, three hundred two thousand, one hundred sixty-one".