87521 has 4 divisors (see below), whose sum is σ = 100032. Its totient is φ = 75012.

The previous prime is 87517. The next prime is 87523. The reversal of 87521 is 12578.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 87521 - 2² = 87517 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87523) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6245 + ... + 6258.

It is an arithmetic number, because the mean of its divisors is an integer number (25008).

2⁸⁷⁵²¹ is an apocalyptic number.

It is an amenable number.

87521 is a deficient number, since it is larger than the sum of its proper divisors (12511).

87521 is a wasteful number, since it uses less digits than its factorization.

87521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12510.

The product of its digits is 560, while the sum is 23.

The square root of 87521 is about 295.8394835041. The cubic root of 87521 is about 44.3987514190.

The spelling of 87521 in words is "eighty-seven thousand, five hundred twenty-one".