1261036121 has 2 divisors, whose sum is σ = 1261036122. Its totient is φ = 1261036120.

The previous prime is 1261036097. The next prime is 1261036123. The reversal of 1261036121 is 1216301621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1118568025 + 142468096 = 33445^2 + 11936^2 .

It is an emirp because it is prime and its reverse (1216301621) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1261036121 - 2¹⁸ = 1260773977 is a prime.

Together with 1261036123, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1261036123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630518060 + 630518061.

It is an arithmetic number, because the mean of its divisors is an integer number (630518061).

Almost surely, 2^1261036121 is an apocalyptic number.

It is an amenable number.

1261036121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261036121 is an equidigital number, since it uses as much as digits as its factorization.

1261036121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 1261036121 is about 35511.0704006511. The cubic root of 1261036121 is about 1080.3782742712.

Adding to 1261036121 its reverse (1216301621), we get a palindrome (2477337742).

The spelling of 1261036121 in words is "one billion, two hundred sixty-one million, thirty-six thousand, one hundred twenty-one".