51102209 has 2 divisors, whose sum is σ = 51102210. Its totient is φ = 51102208.

The previous prime is 51102203. The next prime is 51102211. The reversal of 51102209 is 90220115.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41473600 + 9628609 = 6440^2 + 3103^2 .

It is a cyclic number.

It is not a de Polignac number, because 51102209 - 2⁴ = 51102193 is a prime.

It is a super-2 number, since 2×51102209² = 5222871529359362, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 51102211, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (51102203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25551104 + 25551105.

It is an arithmetic number, because the mean of its divisors is an integer number (25551105).

Almost surely, 2^51102209 is an apocalyptic number.

It is an amenable number.

51102209 is a deficient number, since it is larger than the sum of its proper divisors (1).

51102209 is an equidigital number, since it uses as much as digits as its factorization.

51102209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 180, while the sum is 20.

The square root of 51102209 is about 7148.5809081244. The cubic root of 51102209 is about 371.0905468430.

The spelling of 51102209 in words is "fifty-one million, one hundred two thousand, two hundred nine".