221166776792281 has 2 divisors, whose sum is σ = 221166776792282. Its totient is φ = 221166776792280.

The previous prime is 221166776792279. The next prime is 221166776792341. The reversal of 221166776792281 is 182297677661122.

221166776792281 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., 138993276990681 + 82173499801600 = 11789541^2 + 9064960^2 .

It is a cyclic number.

It is not a de Polignac number, because 221166776792281 - 2¹ = 221166776792279 is a prime.

It is a super-2 number, since 2×221166776792281² (a number of 29 digits) contains 22 as substring.

Together with 221166776792279, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (221166776792201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110583388396140 + 110583388396141.

It is an arithmetic number, because the mean of its divisors is an integer number (110583388396141).

Almost surely, 2^{221166776792281} is an apocalyptic number.

It is an amenable number.

221166776792281 is a deficient number, since it is larger than the sum of its proper divisors (1).

221166776792281 is an equidigital number, since it uses as much as digits as its factorization.

221166776792281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 85349376, while the sum is 67.

The spelling of 221166776792281 in words is "two hundred twenty-one trillion, one hundred sixty-six billion, seven hundred seventy-six million, seven hundred ninety-two thousand, two hundred eighty-one".