211012121221261 has 2 divisors, whose sum is σ = 211012121221262. Its totient is φ = 211012121221260.

The previous prime is 211012121221201. The next prime is 211012121221267. The reversal of 211012121221261 is 162122121210112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 107377054044100 + 103635067177161 = 10362290^2 + 10180131^2 .

It is a cyclic number.

It is not a de Polignac number, because 211012121221261 - 2²¹ = 211012119124109 is a prime.

It is a super-2 number, since 2×211012121221261² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211012121221267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105506060610630 + 105506060610631.

It is an arithmetic number, because the mean of its divisors is an integer number (105506060610631).

Almost surely, 2^{211012121221261} is an apocalyptic number.

It is an amenable number.

211012121221261 is a deficient number, since it is larger than the sum of its proper divisors (1).

211012121221261 is an equidigital number, since it uses as much as digits as its factorization.

211012121221261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 384, while the sum is 25.

Adding to 211012121221261 its reverse (162122121210112), we get a palindrome (373134242431373).

The spelling of 211012121221261 in words is "two hundred eleven trillion, twelve billion, one hundred twenty-one million, two hundred twenty-one thousand, two hundred sixty-one".