51791309 has 2 divisors, whose sum is σ = 51791310. Its totient is φ = 51791308.

The previous prime is 51791293. The next prime is 51791329. The reversal of 51791309 is 90319715.

51791309 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 46854025 + 4937284 = 6845^2 + 2222^2 .

It is a cyclic number.

It is not a de Polignac number, because 51791309 - 2⁴ = 51791293 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51791329) 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, 25895654 + 25895655.

It is an arithmetic number, because the mean of its divisors is an integer number (25895655).

Almost surely, 2^51791309 is an apocalyptic number.

It is an amenable number.

51791309 is a deficient number, since it is larger than the sum of its proper divisors (1).

51791309 is an equidigital number, since it uses as much as digits as its factorization.

51791309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8505, while the sum is 35.

The square root of 51791309 is about 7196.6178862018. The cubic root of 51791309 is about 372.7511247494.

The spelling of 51791309 in words is "fifty-one million, seven hundred ninety-one thousand, three hundred nine".