51031320169 has 2 divisors, whose sum is σ = 51031320170. Its totient is φ = 51031320168.

The previous prime is 51031320167. The next prime is 51031320181. The reversal of 51031320169 is 96102313015.

It is a happy number.

51031320169 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., 48116616025 + 2914704144 = 219355^2 + 53988^2 .

It is a cyclic number.

It is not a de Polignac number, because 51031320169 - 2¹ = 51031320167 is a prime.

It is a super-2 number, since 2×51031320169² (a number of 22 digits) contains 22 as substring.

Together with 51031320167, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 51031320169.

It is not a weakly prime, because it can be changed into another prime (51031320161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25515660084 + 25515660085.

It is an arithmetic number, because the mean of its divisors is an integer number (25515660085).

Almost surely, 2^51031320169 is an apocalyptic number.

It is an amenable number.

51031320169 is a deficient number, since it is larger than the sum of its proper divisors (1).

51031320169 is an equidigital number, since it uses as much as digits as its factorization.

51031320169 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4860, while the sum is 31.

The spelling of 51031320169 in words is "fifty-one billion, thirty-one million, three hundred twenty thousand, one hundred sixty-nine".