78218866836841 has 2 divisors, whose sum is σ = 78218866836842. Its totient is φ = 78218866836840.

The previous prime is 78218866836829. The next prime is 78218866836917. The reversal of 78218866836841 is 14863866881287.

It is an a-pointer prime, because the next prime (78218866836917) can be obtained adding 78218866836841 to its sum of digits (76).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 75538348038400 + 2680518798441 = 8691280^2 + 1637229^2 .

It is a cyclic number.

It is not a de Polignac number, because 78218866836841 - 2²⁷ = 78218732619113 is a prime.

It is a super-2 number, since 2×78218866836841² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78218866836041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39109433418420 + 39109433418421.

It is an arithmetic number, because the mean of its divisors is an integer number (39109433418421).

Almost surely, 2^{78218866836841} is an apocalyptic number.

It is an amenable number.

78218866836841 is a deficient number, since it is larger than the sum of its proper divisors (1).

78218866836841 is an equidigital number, since it uses as much as digits as its factorization.

78218866836841 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1189085184, while the sum is 76.

The spelling of 78218866836841 in words is "seventy-eight trillion, two hundred eighteen billion, eight hundred sixty-six million, eight hundred thirty-six thousand, eight hundred forty-one".