51911281 has 2 divisors, whose sum is σ = 51911282. Its totient is φ = 51911280.

The previous prime is 51911263. The next prime is 51911309. The reversal of 51911281 is 18211915.

It is an a-pointer prime, because the next prime (51911309) can be obtained adding 51911281 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., 29062881 + 22848400 = 5391^2 + 4780^2 .

It is a cyclic number.

It is not a de Polignac number, because 51911281 - 2¹¹ = 51909233 is a prime.

It is a super-2 number, since 2×51911281² = 5389562190121922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (51911231) 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, 25955640 + 25955641.

It is an arithmetic number, because the mean of its divisors is an integer number (25955641).

Almost surely, 2^51911281 is an apocalyptic number.

It is an amenable number.

51911281 is a deficient number, since it is larger than the sum of its proper divisors (1).

51911281 is an equidigital number, since it uses as much as digits as its factorization.

51911281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 720, while the sum is 28.

The square root of 51911281 is about 7204.9483690031. The cubic root of 51911281 is about 373.0387226293.

The spelling of 51911281 in words is "fifty-one million, nine hundred eleven thousand, two hundred eighty-one".