51321808 has 20 divisors (see below), whose sum is σ = 101313828. Its totient is φ = 25176320.

The previous prime is 51321779. The next prime is 51321817. The reversal of 51321808 is 80812315.

51321808 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 21641104 + 29680704 = 4652^2 + 5448^2 .

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 29413 + ... + 31108.

Almost surely, 2^51321808 is an apocalyptic number.

It is an amenable number.

51321808 is a deficient number, since it is larger than the sum of its proper divisors (49992020).

51321808 is a wasteful number, since it uses less digits than its factorization.

51321808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60582 (or 60576 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 51321808 is about 7163.9240643658. The cubic root of 51321808 is about 371.6213436078.

The spelling of 51321808 in words is "fifty-one million, three hundred twenty-one thousand, eight hundred eight".