87209521 has 8 divisors (see below), whose sum is σ = 99927360. Its totient is φ = 74556528.

The previous prime is 87209519. The next prime is 87209527. The reversal of 87209521 is 12590278.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 87209521 - 2¹ = 87209519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (87209527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13291 + ... + 18736.

It is an arithmetic number, because the mean of its divisors is an integer number (12490920).

Almost surely, 2^87209521 is an apocalyptic number.

It is an amenable number.

87209521 is a deficient number, since it is larger than the sum of its proper divisors (12717839).

87209521 is a wasteful number, since it uses less digits than its factorization.

87209521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32423.

The product of its (nonzero) digits is 10080, while the sum is 34.

The square root of 87209521 is about 9338.6038035672. The cubic root of 87209521 is about 443.4601848673.

Adding to 87209521 its reverse (12590278), we get a palindrome (99799799).

The spelling of 87209521 in words is "eighty-seven million, two hundred nine thousand, five hundred twenty-one".