878765676781 has 2 divisors, whose sum is σ = 878765676782. Its totient is φ = 878765676780.

The previous prime is 878765676779. The next prime is 878765676787. The reversal of 878765676781 is 187676567878.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 850148541225 + 28617135556 = 922035^2 + 169166^2 .

It is a cyclic number.

It is not a de Polignac number, because 878765676781 - 2¹ = 878765676779 is a prime.

It is a super-2 number, since 2×878765676781² (a number of 25 digits) contains 22 as substring.

Together with 878765676779, it forms a pair of twin primes.

It is an alternating number because its digits alternate between even and odd.

It is a junction number, because it is equal to n+sod(n) for n = 878765676698 and 878765676707.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (878765676787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 439382838390 + 439382838391.

It is an arithmetic number, because the mean of its divisors is an integer number (439382838391).

Almost surely, 2^878765676781 is an apocalyptic number.

It is an amenable number.

878765676781 is a deficient number, since it is larger than the sum of its proper divisors (1).

878765676781 is an equidigital number, since it uses as much as digits as its factorization.

878765676781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1327656960, while the sum is 76.

The spelling of 878765676781 in words is "eight hundred seventy-eight billion, seven hundred sixty-five million, six hundred seventy-six thousand, seven hundred eighty-one".