51080209 has 2 divisors, whose sum is σ = 51080210. Its totient is φ = 51080208.

The previous prime is 51080207. The next prime is 51080213. The reversal of 51080209 is 90208015.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 48094225 + 2985984 = 6935^2 + 1728^2 .

It is a cyclic number.

It is not a de Polignac number, because 51080209 - 2¹ = 51080207 is a prime.

Together with 51080207, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (51080201) 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, 25540104 + 25540105.

It is an arithmetic number, because the mean of its divisors is an integer number (25540105).

Almost surely, 2^51080209 is an apocalyptic number.

It is an amenable number.

51080209 is a deficient number, since it is larger than the sum of its proper divisors (1).

51080209 is an equidigital number, since it uses as much as digits as its factorization.

51080209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 720, while the sum is 25.

The square root of 51080209 is about 7147.0419755309. The cubic root of 51080209 is about 371.0372864979.

It can be divided in two parts, 5 and 1080209, that multiplied together give a palindrome (5401045).

The spelling of 51080209 in words is "fifty-one million, eighty thousand, two hundred nine".