213113221261 has 2 divisors, whose sum is σ = 213113221262. Its totient is φ = 213113221260.

The previous prime is 213113221219. The next prime is 213113221283. The reversal of 213113221261 is 162122311312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 109875675625 + 103237545636 = 331475^2 + 321306^2 .

It is a cyclic number.

It is not a de Polignac number, because 213113221261 - 2²³ = 213104832653 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213113221861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106556610630 + 106556610631.

It is an arithmetic number, because the mean of its divisors is an integer number (106556610631).

Almost surely, 2^213113221261 is an apocalyptic number.

It is an amenable number.

213113221261 is a deficient number, since it is larger than the sum of its proper divisors (1).

213113221261 is an equidigital number, since it uses as much as digits as its factorization.

213113221261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 864, while the sum is 25.

Adding to 213113221261 its reverse (162122311312), we get a palindrome (375235532573).

The spelling of 213113221261 in words is "two hundred thirteen billion, one hundred thirteen million, two hundred twenty-one thousand, two hundred sixty-one".