878423809 has 2 divisors, whose sum is σ = 878423810. Its totient is φ = 878423808.

The previous prime is 878423807. The next prime is 878423837. The reversal of 878423809 is 908324878.

878423809 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 611820225 + 266603584 = 24735^2 + 16328^2 .

It is a cyclic number.

It is not a de Polignac number, because 878423809 - 2¹ = 878423807 is a prime.

Together with 878423807, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (878423807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 439211904 + 439211905.

It is an arithmetic number, because the mean of its divisors is an integer number (439211905).

Almost surely, 2^878423809 is an apocalyptic number.

It is an amenable number.

878423809 is a deficient number, since it is larger than the sum of its proper divisors (1).

878423809 is an equidigital number, since it uses as much as digits as its factorization.

878423809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 774144, while the sum is 49.

The square root of 878423809 is about 29638.2153477567. The cubic root of 878423809 is about 957.7114936607.

The spelling of 878423809 in words is "eight hundred seventy-eight million, four hundred twenty-three thousand, eight hundred nine".