51512805 has 48 divisors (see below), whose sum is σ = 95275440. Its totient is φ = 25746432.

The previous prime is 51512803. The next prime is 51512821. The reversal of 51512805 is 50821515.

It can be written as a sum of positive squares in 8 ways, for example, as 1640961 + 49871844 = 1281^2 + 7062^2 .

It is not a de Polignac number, because 51512805 - 2¹ = 51512803 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51512803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 220969 + ... + 221201.

It is an arithmetic number, because the mean of its divisors is an integer number (1984905).

Almost surely, 2^51512805 is an apocalyptic number.

It is an amenable number.

51512805 is a deficient number, since it is larger than the sum of its proper divisors (43762635).

51512805 is a wasteful number, since it uses less digits than its factorization.

51512805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 295 (or 258 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 27.

The square root of 51512805 is about 7177.2421583781. The cubic root of 51512805 is about 372.0817761600.

The spelling of 51512805 in words is "fifty-one million, five hundred twelve thousand, eight hundred five".