51261216289 has 2 divisors, whose sum is σ = 51261216290. Its totient is φ = 51261216288.

The previous prime is 51261216199. The next prime is 51261216299. The reversal of 51261216289 is 98261216215.

51261216289 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29926232064 + 21334984225 = 172992^2 + 146065^2 .

It is a cyclic number.

It is not a de Polignac number, because 51261216289 - 2⁷ = 51261216161 is a prime.

It is not a weakly prime, because it can be changed into another prime (51261216299) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25630608144 + 25630608145.

It is an arithmetic number, because the mean of its divisors is an integer number (25630608145).

Almost surely, 2^51261216289 is an apocalyptic number.

It is an amenable number.

51261216289 is a deficient number, since it is larger than the sum of its proper divisors (1).

51261216289 is an equidigital number, since it uses as much as digits as its factorization.

51261216289 is an evil number, because the sum of its binary digits is even.

The product of its digits is 103680, while the sum is 43.

The spelling of 51261216289 in words is "fifty-one billion, two hundred sixty-one million, two hundred sixteen thousand, two hundred eighty-nine".