51008281 has 2 divisors, whose sum is σ = 51008282. Its totient is φ = 51008280.

The previous prime is 51008263. The next prime is 51008329. The reversal of 51008281 is 18280015.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50993881 + 14400 = 7141^2 + 120^2 .

It is a cyclic number.

It is not a de Polignac number, because 51008281 - 2⁵ = 51008249 is a prime.

It is a super-2 number, since 2×51008281² = 5203689461149922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (51005281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25504140 + 25504141.

It is an arithmetic number, because the mean of its divisors is an integer number (25504141).

Almost surely, 2^51008281 is an apocalyptic number.

It is an amenable number.

51008281 is a deficient number, since it is larger than the sum of its proper divisors (1).

51008281 is an equidigital number, since it uses as much as digits as its factorization.

51008281 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 640, while the sum is 25.

The square root of 51008281 is about 7142.0081909782. The cubic root of 51008281 is about 370.8630474135.

Adding to 51008281 its reverse (18280015), we get a palindrome (69288296).

It can be divided in two parts, 5 and 1008281, that multiplied together give a palindrome (5041405).

The spelling of 51008281 in words is "fifty-one million, eight thousand, two hundred eighty-one".