51217609 has 2 divisors, whose sum is σ = 51217610. Its totient is φ = 51217608.

The previous prime is 51217571. The next prime is 51217627. The reversal of 51217609 is 90671215.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29127609 + 22090000 = 5397^2 + 4700^2 .

It is a cyclic number.

It is not a de Polignac number, because 51217609 - 2¹¹ = 51215561 is a prime.

It is equal to p_3069706 and since 51217609 and 3069706 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (51217669) 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, 25608804 + 25608805.

It is an arithmetic number, because the mean of its divisors is an integer number (25608805).

Almost surely, 2^51217609 is an apocalyptic number.

It is an amenable number.

51217609 is a deficient number, since it is larger than the sum of its proper divisors (1).

51217609 is an equidigital number, since it uses as much as digits as its factorization.

51217609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3780, while the sum is 31.

The square root of 51217609 is about 7156.6478885020. The cubic root of 51217609 is about 371.3696714648.

The spelling of 51217609 in words is "fifty-one million, two hundred seventeen thousand, six hundred nine".