51612021161 has 2 divisors, whose sum is σ = 51612021162. Its totient is φ = 51612021160.

The previous prime is 51612021157. The next prime is 51612021163. The reversal of 51612021161 is 16112021615.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39573542761 + 12038478400 = 198931^2 + 109720^2 .

It is a cyclic number.

It is not a de Polignac number, because 51612021161 - 2² = 51612021157 is a prime.

Together with 51612021163, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 51612021161.

It is not a weakly prime, because it can be changed into another prime (51612021163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25806010580 + 25806010581.

It is an arithmetic number, because the mean of its divisors is an integer number (25806010581).

Almost surely, 2^51612021161 is an apocalyptic number.

It is an amenable number.

51612021161 is a deficient number, since it is larger than the sum of its proper divisors (1).

51612021161 is an equidigital number, since it uses as much as digits as its factorization.

51612021161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 720, while the sum is 26.

Adding to 51612021161 its reverse (16112021615), we get a palindrome (67724042776).

The spelling of 51612021161 in words is "fifty-one billion, six hundred twelve million, twenty-one thousand, one hundred sixty-one".