221011031161 has 2 divisors, whose sum is σ = 221011031162. Its totient is φ = 221011031160.

The previous prime is 221011031159. The next prime is 221011031177. The reversal of 221011031161 is 161130110122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 208588591225 + 12422439936 = 456715^2 + 111456^2 .

It is a cyclic number.

It is not a de Polignac number, because 221011031161 - 2¹ = 221011031159 is a prime.

Together with 221011031159, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (221011037161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110505515580 + 110505515581.

It is an arithmetic number, because the mean of its divisors is an integer number (110505515581).

Almost surely, 2^221011031161 is an apocalyptic number.

It is an amenable number.

221011031161 is a deficient number, since it is larger than the sum of its proper divisors (1).

221011031161 is an equidigital number, since it uses as much as digits as its factorization.

221011031161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 19.

Adding to 221011031161 its reverse (161130110122), we get a palindrome (382141141283).

The spelling of 221011031161 in words is "two hundred twenty-one billion, eleven million, thirty-one thousand, one hundred sixty-one".