51809893 has 2 divisors, whose sum is σ = 51809894. Its totient is φ = 51809892.

The previous prime is 51809831. The next prime is 51809899. The reversal of 51809893 is 39890815.

51809893 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., 33431524 + 18378369 = 5782^2 + 4287^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51809893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51809899) 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, 25904946 + 25904947.

It is an arithmetic number, because the mean of its divisors is an integer number (25904947).

Almost surely, 2^51809893 is an apocalyptic number.

It is an amenable number.

51809893 is a deficient number, since it is larger than the sum of its proper divisors (1).

51809893 is an equidigital number, since it uses as much as digits as its factorization.

51809893 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 77760, while the sum is 43.

The square root of 51809893 is about 7197.9089324609. The cubic root of 51809893 is about 372.7957035192.

The spelling of 51809893 in words is "fifty-one million, eight hundred nine thousand, eight hundred ninety-three".