51809993 has 2 divisors, whose sum is σ = 51809994. Its totient is φ = 51809992.

The previous prime is 51809987. The next prime is 51810023. The reversal of 51809993 is 39990815.

51809993 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., 37002889 + 14807104 = 6083^2 + 3848^2 .

It is a cyclic number.

It is not a de Polignac number, because 51809993 - 2⁴ = 51809977 is a prime.

It is not a weakly prime, because it can be changed into another prime (51809893) 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, 25904996 + 25904997.

It is an arithmetic number, because the mean of its divisors is an integer number (25904997).

Almost surely, 2^51809993 is an apocalyptic number.

It is an amenable number.

51809993 is a deficient number, since it is larger than the sum of its proper divisors (1).

51809993 is an equidigital number, since it uses as much as digits as its factorization.

51809993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 87480, while the sum is 44.

The square root of 51809993 is about 7197.9158789194. The cubic root of 51809993 is about 372.7959433675.

The spelling of 51809993 in words is "fifty-one million, eight hundred nine thousand, nine hundred ninety-three".