51500813 has 12 divisors (see below), whose sum is σ = 64518300. Its totient is φ = 40747392.

The previous prime is 51500783. The next prime is 51500863. The reversal of 51500813 is 31800515.

51500813 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 18472804 + 33028009 = 4298^2 + 5747^2 .

It is not a de Polignac number, because 51500813 - 2⁸ = 51500557 is a prime.

51500813 is a modest number, since divided by 813 gives 515 as remainder.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51500863) 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 in 11 ways as a sum of consecutive naturals, for example, 39788 + ... + 41061.

It is an arithmetic number, because the mean of its divisors is an integer number (5376525).

Almost surely, 2^51500813 is an apocalyptic number.

It is an amenable number.

51500813 is a deficient number, since it is larger than the sum of its proper divisors (13017487).

51500813 is a wasteful number, since it uses less digits than its factorization.

51500813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80876 (or 80869 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 23.

The square root of 51500813 is about 7176.4066913742. The cubic root of 51500813 is about 372.0529008092.

The spelling of 51500813 in words is "fifty-one million, five hundred thousand, eight hundred thirteen".