871811540 has 12 divisors (see below), whose sum is σ = 1830804276. Its totient is φ = 348724608.

The previous prime is 871811537. The next prime is 871811579. The reversal of 871811540 is 45118178.

It can be written as a sum of positive squares in 2 ways, for example, as 354794896 + 517016644 = 18836^2 + 22738^2 .

It is a super-2 number, since 2×871811540² = 1520110722554343200, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 871811540.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21795269 + ... + 21795308.

It is an arithmetic number, because the mean of its divisors is an integer number (152567023).

Almost surely, 2^871811540 is an apocalyptic number.

It is an amenable number.

871811540 is an abundant number, since it is smaller than the sum of its proper divisors (958992736).

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

871811540 is a wasteful number, since it uses less digits than its factorization.

871811540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43590586 (or 43590584 counting only the distinct ones).

The product of its (nonzero) digits is 8960, while the sum is 35.

The square root of 871811540 is about 29526.4549175820. The cubic root of 871811540 is about 955.3024050771.

The spelling of 871811540 in words is "eight hundred seventy-one million, eight hundred eleven thousand, five hundred forty".