51005239 has 4 divisors (see below), whose sum is σ = 51967656. Its totient is φ = 50042824.

The previous prime is 51005209. The next prime is 51005249. The reversal of 51005239 is 93250015.

51005239 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 is a cyclic number.

It is not a de Polignac number, because 51005239 - 2¹¹ = 51003191 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51005209) 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 3 ways as a sum of consecutive naturals, for example, 481129 + ... + 481234.

It is an arithmetic number, because the mean of its divisors is an integer number (12991914).

Almost surely, 2^51005239 is an apocalyptic number.

51005239 is a deficient number, since it is larger than the sum of its proper divisors (962417).

51005239 is an equidigital number, since it uses as much as digits as its factorization.

51005239 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 962416.

The product of its (nonzero) digits is 1350, while the sum is 25.

The square root of 51005239 is about 7141.7952224913. The cubic root of 51005239 is about 370.8556748340.

The spelling of 51005239 in words is "fifty-one million, five thousand, two hundred thirty-nine".