871565220 has 72 divisors (see below), whose sum is σ = 2758706496. Its totient is φ = 222311232.

The previous prime is 871565171. The next prime is 871565221. The reversal of 871565220 is 22565178.

It is a happy number.

871565220 is a `hidden beast` number, since 8 + 71 + 565 + 2 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (871565221) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 101122 + ... + 109401.

It is an arithmetic number, because the mean of its divisors is an integer number (38315368).

Almost surely, 2^871565220 is an apocalyptic number.

It is an amenable number.

871565220 is an abundant number, since it is smaller than the sum of its proper divisors (1887141276).

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

871565220 is a wasteful number, since it uses less digits than its factorization.

871565220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210561 (or 210556 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 36.

The square root of 871565220 is about 29522.2834482701. The cubic root of 871565220 is about 955.2124268183.

The spelling of 871565220 in words is "eight hundred seventy-one million, five hundred sixty-five thousand, two hundred twenty".