51313281 has 8 divisors (see below), whose sum is σ = 72018720. Its totient is φ = 32408352.

The previous prime is 51313247. The next prime is 51313289. The reversal of 51313281 is 18231315.

51313281 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 51313281 - 2¹⁰ = 51312257 is a prime.

It is a super-2 number, since 2×51313281² = 5266105613969922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (51313289) 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 7 ways as a sum of consecutive naturals, for example, 450060 + ... + 450173.

It is an arithmetic number, because the mean of its divisors is an integer number (9002340).

Almost surely, 2^51313281 is an apocalyptic number.

It is an amenable number.

51313281 is a deficient number, since it is larger than the sum of its proper divisors (20705439).

51313281 is a wasteful number, since it uses less digits than its factorization.

51313281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 900255.

The product of its digits is 720, while the sum is 24.

The square root of 51313281 is about 7163.3289049156. The cubic root of 51313281 is about 371.6007611249.

Adding to 51313281 its reverse (18231315), we get a palindrome (69544596).

The spelling of 51313281 in words is "fifty-one million, three hundred thirteen thousand, two hundred eighty-one".