51131836109 has 2 divisors, whose sum is σ = 51131836110. Its totient is φ = 51131836108.

The previous prime is 51131836099. The next prime is 51131836117. The reversal of 51131836109 is 90163813115.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31656238084 + 19475598025 = 177922^2 + 139555^2 .

It is a cyclic number.

It is not a de Polignac number, because 51131836109 - 2²⁴ = 51115058893 is a prime.

It is a super-2 number, since 2×51131836109² (a number of 22 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51131836409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25565918054 + 25565918055.

It is an arithmetic number, because the mean of its divisors is an integer number (25565918055).

Almost surely, 2^51131836109 is an apocalyptic number.

It is an amenable number.

51131836109 is a deficient number, since it is larger than the sum of its proper divisors (1).

51131836109 is an equidigital number, since it uses as much as digits as its factorization.

51131836109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 19440, while the sum is 38.

The spelling of 51131836109 in words is "fifty-one billion, one hundred thirty-one million, eight hundred thirty-six thousand, one hundred nine".