51320565 has 24 divisors (see below), whose sum is σ = 89122488. Its totient is φ = 27319680.

The previous prime is 51320527. The next prime is 51320597. The reversal of 51320565 is 56502315.

It can be written as a sum of positive squares in 4 ways, for example, as 298116 + 51022449 = 546^2 + 7143^2 .

It is not a de Polignac number, because 51320565 - 2¹² = 51316469 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 45387 + ... + 46503.

It is an arithmetic number, because the mean of its divisors is an integer number (3713437).

Almost surely, 2^51320565 is an apocalyptic number.

It is an amenable number.

51320565 is a deficient number, since it is larger than the sum of its proper divisors (37801923).

51320565 is a wasteful number, since it uses less digits than its factorization.

51320565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2149 (or 2146 counting only the distinct ones).

The product of its (nonzero) digits is 4500, while the sum is 27.

The square root of 51320565 is about 7163.8373097105. The cubic root of 51320565 is about 371.6183433949.

The spelling of 51320565 in words is "fifty-one million, three hundred twenty thousand, five hundred sixty-five".