878631409 has 4 divisors (see below), whose sum is σ = 878888304. Its totient is φ = 878374516.

The previous prime is 878631379. The next prime is 878631437. The reversal of 878631409 is 904136878.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 878631409 - 2¹⁹ = 878107121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (878631469) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 123247 + ... + 130180.

It is an arithmetic number, because the mean of its divisors is an integer number (219722076).

Almost surely, 2^878631409 is an apocalyptic number.

It is an amenable number.

878631409 is a deficient number, since it is larger than the sum of its proper divisors (256895).

878631409 is a wasteful number, since it uses less digits than its factorization.

878631409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 256894.

The product of its (nonzero) digits is 290304, while the sum is 46.

The square root of 878631409 is about 29641.7173760226. The cubic root of 878631409 is about 957.7869338007.

The spelling of 878631409 in words is "eight hundred seventy-eight million, six hundred thirty-one thousand, four hundred nine".