51039985 has 12 divisors (see below), whose sum is σ = 64643508. Its totient is φ = 38681568.

The previous prime is 51039973. The next prime is 51040019. The reversal of 51039985 is 58993015.

It can be written as a sum of positive squares in 2 ways, for example, as 18766224 + 32273761 = 4332^2 + 5681^2 .

It is not a de Polignac number, because 51039985 - 2¹¹ = 51037937 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12334 + ... + 15943.

It is an arithmetic number, because the mean of its divisors is an integer number (5386959).

Almost surely, 2^51039985 is an apocalyptic number.

It is an amenable number.

51039985 is a deficient number, since it is larger than the sum of its proper divisors (13603523).

51039985 is a wasteful number, since it uses less digits than its factorization.

51039985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28320 (or 28301 counting only the distinct ones).

The product of its (nonzero) digits is 48600, while the sum is 40.

The square root of 51039985 is about 7144.2273899982. The cubic root of 51039985 is about 370.9398676647.

The spelling of 51039985 in words is "fifty-one million, thirty-nine thousand, nine hundred eighty-five".