51508809 has 12 divisors (see below), whose sum is σ = 81165552. Its totient is φ = 31217400.

The previous prime is 51508789. The next prime is 51508811. The reversal of 51508809 is 90880515.

51508809 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 51508809 - 2¹⁵ = 51476041 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51508819) 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, 260047 + ... + 260244.

It is an arithmetic number, because the mean of its divisors is an integer number (6763796).

Almost surely, 2^51508809 is an apocalyptic number.

It is an amenable number.

51508809 is a deficient number, since it is larger than the sum of its proper divisors (29656743).

51508809 is a wasteful number, since it uses less digits than its factorization.

51508809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 520308 (or 520305 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 36.

The square root of 51508809 is about 7176.9637730728. The cubic root of 51508809 is about 372.0721547515.

The spelling of 51508809 in words is "fifty-one million, five hundred eight thousand, eight hundred nine".