87021 has 16 divisors (see below), whose sum is σ = 141120. Its totient is φ = 52560.

The previous prime is 87013. The next prime is 87037. The reversal of 87021 is 12078.

It is not a de Polignac number, because 87021 - 2³ = 87013 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 86985 and 87003.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 87021.

It is not an unprimeable number, because it can be changed into a prime (87011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 151 + ... + 443.

It is an arithmetic number, because the mean of its divisors is an integer number (8820).

2⁸⁷⁰²¹ is an apocalyptic number.

It is an amenable number.

87021 is a deficient number, since it is larger than the sum of its proper divisors (54099).

87021 is a wasteful number, since it uses less digits than its factorization.

87021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 313 (or 307 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 18.

The square root of 87021 is about 294.9932202611. The cubic root of 87021 is about 44.3140411408.

Adding to 87021 its reverse (12078), we get a palindrome (99099).

The spelling of 87021 in words is "eighty-seven thousand, twenty-one".