127195765421 has 2 divisors, whose sum is σ = 127195765422. Its totient is φ = 127195765420.

The previous prime is 127195765409. The next prime is 127195765423. The reversal of 127195765421 is 124567591721.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 93262441321 + 33933324100 = 305389^2 + 184210^2 .

It is an emirp because it is prime and its reverse (124567591721) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-127195765421 is a prime.

Together with 127195765423, 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 127195765421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (127195765423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 63597882710 + 63597882711.

It is an arithmetic number, because the mean of its divisors is an integer number (63597882711).

Almost surely, 2^127195765421 is an apocalyptic number.

It is an amenable number.

127195765421 is a deficient number, since it is larger than the sum of its proper divisors (1).

127195765421 is an equidigital number, since it uses as much as digits as its factorization.

127195765421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1058400, while the sum is 50.

The spelling of 127195765421 in words is "one hundred twenty-seven billion, one hundred ninety-five million, seven hundred sixty-five thousand, four hundred twenty-one".