87820 has 12 divisors (see below), whose sum is σ = 184464. Its totient is φ = 35120.

The previous prime is 87811. The next prime is 87833. The reversal of 87820 is 2878.

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, 2176 + ... + 2215.

It is an arithmetic number, because the mean of its divisors is an integer number (15372).

2⁸⁷⁸²⁰ is an apocalyptic number.

It is an amenable number.

87820 is an abundant number, since it is smaller than the sum of its proper divisors (96644).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (92232).

87820 is a wasteful number, since it uses less digits than its factorization.

87820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4400 (or 4398 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 25.

The square root of 87820 is about 296.3443942443. The cubic root of 87820 is about 44.4492541091.

It can be divided in two parts, 878 and 20, that added together give a palindrome (898).

The spelling of 87820 in words is "eighty-seven thousand, eight hundred twenty".