51115109 has 2 divisors, whose sum is σ = 51115110. Its totient is φ = 51115108.

The previous prime is 51115079. The next prime is 51115117. The reversal of 51115109 is 90151115.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41964484 + 9150625 = 6478^2 + 3025^2 .

It is a cyclic number.

It is not a de Polignac number, because 51115109 - 2⁸ = 51114853 is a prime.

It is a super-2 number, since 2×51115109² = 5225508736163762, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51115159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25557554 + 25557555.

It is an arithmetic number, because the mean of its divisors is an integer number (25557555).

Almost surely, 2^51115109 is an apocalyptic number.

It is an amenable number.

51115109 is a deficient number, since it is larger than the sum of its proper divisors (1).

51115109 is an equidigital number, since it uses as much as digits as its factorization.

51115109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 225, while the sum is 23.

The square root of 51115109 is about 7149.4831281709. The cubic root of 51115109 is about 371.1217696636.

The spelling of 51115109 in words is "fifty-one million, one hundred fifteen thousand, one hundred nine".