51665670169 has 2 divisors, whose sum is σ = 51665670170. Its totient is φ = 51665670168.

The previous prime is 51665670167. The next prime is 51665670193. The reversal of 51665670169 is 96107656615.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26476171225 + 25189498944 = 162715^2 + 158712^2 .

It is a cyclic number.

It is not a de Polignac number, because 51665670169 - 2¹ = 51665670167 is a prime.

It is a super-2 number, since 2×51665670169² (a number of 22 digits) contains 22 as substring.

Together with 51665670167, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (51665670163) 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, 25832835084 + 25832835085.

It is an arithmetic number, because the mean of its divisors is an integer number (25832835085).

Almost surely, 2^51665670169 is an apocalyptic number.

It is an amenable number.

51665670169 is a deficient number, since it is larger than the sum of its proper divisors (1).

51665670169 is an equidigital number, since it uses as much as digits as its factorization.

51665670169 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2041200, while the sum is 52.

The spelling of 51665670169 in words is "fifty-one billion, six hundred sixty-five million, six hundred seventy thousand, one hundred sixty-nine".