78322065881 has 2 divisors, whose sum is σ = 78322065882. Its totient is φ = 78322065880.

The previous prime is 78322065863. The next prime is 78322065883. The reversal of 78322065881 is 18856022387.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 56746862656 + 21575203225 = 238216^2 + 146885^2 .

It is an emirp because it is prime and its reverse (18856022387) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78322065881 - 2¹⁰ = 78322064857 is a prime.

It is a super-2 number, since 2×78322065881² (a number of 23 digits) contains 22 as substring.

Together with 78322065883, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (78322065883) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39161032940 + 39161032941.

It is an arithmetic number, because the mean of its divisors is an integer number (39161032941).

Almost surely, 2^78322065881 is an apocalyptic number.

It is an amenable number.

78322065881 is a deficient number, since it is larger than the sum of its proper divisors (1).

78322065881 is an equidigital number, since it uses as much as digits as its factorization.

78322065881 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1290240, while the sum is 50.

The spelling of 78322065881 in words is "seventy-eight billion, three hundred twenty-two million, sixty-five thousand, eight hundred eighty-one".