51287191 has 2 divisors, whose sum is σ = 51287192. Its totient is φ = 51287190.

The previous prime is 51287179. The next prime is 51287209. The reversal of 51287191 is 19178215.

It is a happy number.

51287191 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51287191 - 2²¹ = 49190039 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51287161) 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 as a sum of consecutive naturals, namely, 25643595 + 25643596.

It is an arithmetic number, because the mean of its divisors is an integer number (25643596).

Almost surely, 2^51287191 is an apocalyptic number.

51287191 is a deficient number, since it is larger than the sum of its proper divisors (1).

51287191 is an equidigital number, since it uses as much as digits as its factorization.

51287191 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5040, while the sum is 34.

The square root of 51287191 is about 7161.5075926791. The cubic root of 51287191 is about 371.5377708862.

The spelling of 51287191 in words is "fifty-one million, two hundred eighty-seven thousand, one hundred ninety-one".