51407281 has 2 divisors, whose sum is σ = 51407282. Its totient is φ = 51407280.

The previous prime is 51407273. The next prime is 51407309. The reversal of 51407281 is 18270415.

It is an a-pointer prime, because the next prime (51407309) can be obtained adding 51407281 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 43678881 + 7728400 = 6609^2 + 2780^2 .

It is a cyclic number.

It is not a de Polignac number, because 51407281 - 2³ = 51407273 is a prime.

It is a super-2 number, since 2×51407281² = 5285417079625922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (51407581) 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, 25703640 + 25703641.

It is an arithmetic number, because the mean of its divisors is an integer number (25703641).

Almost surely, 2^51407281 is an apocalyptic number.

It is an amenable number.

51407281 is a deficient number, since it is larger than the sum of its proper divisors (1).

51407281 is an equidigital number, since it uses as much as digits as its factorization.

51407281 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2240, while the sum is 28.

The square root of 51407281 is about 7169.8870981348. The cubic root of 51407281 is about 371.8275325898.

Adding to 51407281 its reverse (18270415), we get a palindrome (69677696).

It can be divided in two parts, 5140 and 7281, that added together give a palindrome (12421).

The spelling of 51407281 in words is "fifty-one million, four hundred seven thousand, two hundred eighty-one".