87005521 has 4 divisors (see below), whose sum is σ = 87631600. Its totient is φ = 86379444.

The previous prime is 87005509. The next prime is 87005531. The reversal of 87005521 is 12550078.

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 a cyclic number.

It is not a de Polignac number, because 87005521 - 2⁷ = 87005393 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 87005521.

It is not an unprimeable number, because it can be changed into a prime (87005531) 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, 312831 + ... + 313108.

It is an arithmetic number, because the mean of its divisors is an integer number (21907900).

Almost surely, 2^87005521 is an apocalyptic number.

It is an amenable number.

87005521 is a deficient number, since it is larger than the sum of its proper divisors (626079).

87005521 is a wasteful number, since it uses less digits than its factorization.

87005521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 626078.

The product of its (nonzero) digits is 2800, while the sum is 28.

The square root of 87005521 is about 9327.6750050589. The cubic root of 87005521 is about 443.1141350799.

Adding to 87005521 its reverse (12550078), we get a palindrome (99555599).

The spelling of 87005521 in words is "eighty-seven million, five thousand, five hundred twenty-one".