871685778 has 16 divisors (see below), whose sum is σ = 1845923040. Its totient is φ = 273470016.

The previous prime is 871685777. The next prime is 871685779. The reversal of 871685778 is 877586178.

It is an interprime number because it is at equal distance from previous prime (871685777) and next prime (871685779).

It is not an unprimeable number, because it can be changed into a prime (871685777) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4272868 + ... + 4273071.

It is an arithmetic number, because the mean of its divisors is an integer number (115370190).

Almost surely, 2^871685778 is an apocalyptic number.

871685778 is an abundant number, since it is smaller than the sum of its proper divisors (974237262).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

871685778 is a wasteful number, since it uses less digits than its factorization.

871685778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8545961.

The product of its digits is 5268480, while the sum is 57.

The square root of 871685778 is about 29524.3251912724. The cubic root of 871685778 is about 955.2564675807.

The spelling of 871685778 in words is "eight hundred seventy-one million, six hundred eighty-five thousand, seven hundred seventy-eight".