2561346121 has 2 divisors, whose sum is σ = 2561346122. Its totient is φ = 2561346120.

The previous prime is 2561346097. The next prime is 2561346131. The reversal of 2561346121 is 1216431652.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2412774400 + 148571721 = 49120^2 + 12189^2 .

It is a cyclic number.

It is not a de Polignac number, because 2561346121 - 2¹⁵ = 2561313353 is a prime.

It is not a weakly prime, because it can be changed into another prime (2561346131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1280673060 + 1280673061.

It is an arithmetic number, because the mean of its divisors is an integer number (1280673061).

Almost surely, 2^2561346121 is an apocalyptic number.

It is an amenable number.

2561346121 is a deficient number, since it is larger than the sum of its proper divisors (1).

2561346121 is an equidigital number, since it uses as much as digits as its factorization.

2561346121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8640, while the sum is 31.

The square root of 2561346121 is about 50609.7433405861. The cubic root of 2561346121 is about 1368.2204897572.

Adding to 2561346121 its reverse (1216431652), we get a palindrome (3777777773).

The spelling of 2561346121 in words is "two billion, five hundred sixty-one million, three hundred forty-six thousand, one hundred twenty-one".