2121101261 has 2 divisors, whose sum is σ = 2121101262. Its totient is φ = 2121101260.

The previous prime is 2121101197. The next prime is 2121101263. The reversal of 2121101261 is 1621011212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1835694025 + 285407236 = 42845^2 + 16894^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121101261 - 2⁶ = 2121101197 is a prime.

Together with 2121101263, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2121101263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060550630 + 1060550631.

It is an arithmetic number, because the mean of its divisors is an integer number (1060550631).

Almost surely, 2^2121101261 is an apocalyptic number.

It is an amenable number.

2121101261 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121101261 is an equidigital number, since it uses as much as digits as its factorization.

2121101261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48, while the sum is 17.

The square root of 2121101261 is about 46055.4151104949. The cubic root of 2121101261 is about 1284.8540586324.

Adding to 2121101261 its reverse (1621011212), we get a palindrome (3742112473).

The spelling of 2121101261 in words is "two billion, one hundred twenty-one million, one hundred one thousand, two hundred sixty-one".