51018865 has 4 divisors (see below), whose sum is σ = 61222644. Its totient is φ = 40815088.

The previous prime is 51018841. The next prime is 51018871. The reversal of 51018865 is 56881015.

51018865 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13454224 + 37564641 = 3668^2 + 6129^2 .

It is a cyclic number.

It is not a de Polignac number, because 51018865 - 2⁵ = 51018833 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 51018865.

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, 5101882 + ... + 5101891.

It is an arithmetic number, because the mean of its divisors is an integer number (15305661).

Almost surely, 2^51018865 is an apocalyptic number.

It is an amenable number.

51018865 is a deficient number, since it is larger than the sum of its proper divisors (10203779).

51018865 is a wasteful number, since it uses less digits than its factorization.

51018865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10203778.

The product of its (nonzero) digits is 9600, while the sum is 34.

The square root of 51018865 is about 7142.7491206118. The cubic root of 51018865 is about 370.8886964713. Note that the first 3 decimals are identical.

The spelling of 51018865 in words is "fifty-one million, eighteen thousand, eight hundred sixty-five".