878845645661 has 2 divisors, whose sum is σ = 878845645662. Its totient is φ = 878845645660.

The previous prime is 878845645621. The next prime is 878845645693. The reversal of 878845645661 is 166546548878.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 864611724025 + 14233921636 = 929845^2 + 119306^2 .

It is a cyclic number.

It is not a de Polignac number, because 878845645661 - 2¹⁰ = 878845644637 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 878845645591 and 878845645600.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (878845645621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 439422822830 + 439422822831.

It is an arithmetic number, because the mean of its divisors is an integer number (439422822831).

Almost surely, 2^878845645661 is an apocalyptic number.

It is an amenable number.

878845645661 is a deficient number, since it is larger than the sum of its proper divisors (1).

878845645661 is an equidigital number, since it uses as much as digits as its factorization.

878845645661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 309657600, while the sum is 68.

The spelling of 878845645661 in words is "eight hundred seventy-eight billion, eight hundred forty-five million, six hundred forty-five thousand, six hundred sixty-one".