212221564081 has 2 divisors, whose sum is σ = 212221564082. Its totient is φ = 212221564080.

The previous prime is 212221563991. The next prime is 212221564111. The reversal of 212221564081 is 180465122212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 210758119056 + 1463445025 = 459084^2 + 38255^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-212221564081 is a prime.

It is a super-2 number, since 2×212221564081² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (212221564781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106110782040 + 106110782041.

It is an arithmetic number, because the mean of its divisors is an integer number (106110782041).

Almost surely, 2^212221564081 is an apocalyptic number.

It is an amenable number.

212221564081 is a deficient number, since it is larger than the sum of its proper divisors (1).

212221564081 is an equidigital number, since it uses as much as digits as its factorization.

212221564081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15360, while the sum is 34.

Adding to 212221564081 its reverse (180465122212), we get a palindrome (392686686293).

The spelling of 212221564081 in words is "two hundred twelve billion, two hundred twenty-one million, five hundred sixty-four thousand, eighty-one".