51278009 has 2 divisors, whose sum is σ = 51278010. Its totient is φ = 51278008.

The previous prime is 51277997. The next prime is 51278027. The reversal of 51278009 is 90087215.

51278009 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 can be written as a sum of positive squares in only one way, i.e., 42445225 + 8832784 = 6515^2 + 2972^2 .

It is a cyclic number.

It is not a de Polignac number, because 51278009 - 2⁸ = 51277753 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (51278039) 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, 25639004 + 25639005.

It is an arithmetic number, because the mean of its divisors is an integer number (25639005).

Almost surely, 2^51278009 is an apocalyptic number.

It is an amenable number.

51278009 is a deficient number, since it is larger than the sum of its proper divisors (1).

51278009 is an equidigital number, since it uses as much as digits as its factorization.

51278009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5040, while the sum is 32.

The square root of 51278009 is about 7160.8664978479. The cubic root of 51278009 is about 371.5155972963.

The spelling of 51278009 in words is "fifty-one million, two hundred seventy-eight thousand, nine".