878819861 has 2 divisors, whose sum is σ = 878819862. Its totient is φ = 878819860.

The previous prime is 878819839. The next prime is 878819867. The reversal of 878819861 is 168918878.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 703257361 + 175562500 = 26519^2 + 13250^2 .

It is a cyclic number.

It is not a de Polignac number, because 878819861 - 2⁶ = 878819797 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 878819797 and 878819806.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (878819867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 439409930 + 439409931.

It is an arithmetic number, because the mean of its divisors is an integer number (439409931).

Almost surely, 2^878819861 is an apocalyptic number.

It is an amenable number.

878819861 is a deficient number, since it is larger than the sum of its proper divisors (1).

878819861 is an equidigital number, since it uses as much as digits as its factorization.

878819861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1548288, while the sum is 56.

The square root of 878819861 is about 29644.8960362488. The cubic root of 878819861 is about 957.8554054254.

The spelling of 878819861 in words is "eight hundred seventy-eight million, eight hundred nineteen thousand, eight hundred sixty-one".