87135521 has 4 divisors (see below), whose sum is σ = 95056944. Its totient is φ = 79214100.

The previous prime is 87135493. The next prime is 87135541. The reversal of 87135521 is 12553178.

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 87135521 - 2¹⁰ = 87134497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (87135541) 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 3 ways as a sum of consecutive naturals, for example, 3960695 + ... + 3960716.

It is an arithmetic number, because the mean of its divisors is an integer number (23764236).

Almost surely, 2^87135521 is an apocalyptic number.

It is an amenable number.

87135521 is a deficient number, since it is larger than the sum of its proper divisors (7921423).

87135521 is a wasteful number, since it uses less digits than its factorization.

87135521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7921422.

The product of its digits is 8400, while the sum is 32.

The square root of 87135521 is about 9334.6409143577. The cubic root of 87135521 is about 443.3347194384.

Adding to 87135521 its reverse (12553178), we get a palindrome (99688699).

The spelling of 87135521 in words is "eighty-seven million, one hundred thirty-five thousand, five hundred twenty-one".