2126261561 has 2 divisors, whose sum is σ = 2126261562. Its totient is φ = 2126261560.

The previous prime is 2126261513. The next prime is 2126261569. The reversal of 2126261561 is 1651626212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1410378025 + 715883536 = 37555^2 + 26756^2 .

It is a cyclic number.

It is not a de Polignac number, because 2126261561 - 2⁶ = 2126261497 is a prime.

It is not a weakly prime, because it can be changed into another prime (2126261569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1063130780 + 1063130781.

It is an arithmetic number, because the mean of its divisors is an integer number (1063130781).

Almost surely, 2^2126261561 is an apocalyptic number.

It is an amenable number.

2126261561 is a deficient number, since it is larger than the sum of its proper divisors (1).

2126261561 is an equidigital number, since it uses as much as digits as its factorization.

2126261561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8640, while the sum is 32.

The square root of 2126261561 is about 46111.4038064338. The cubic root of 2126261561 is about 1285.8951629259.

Adding to 2126261561 its reverse (1651626212), we get a palindrome (3777887773).

The spelling of 2126261561 in words is "two billion, one hundred twenty-six million, two hundred sixty-one thousand, five hundred sixty-one".