87823521 has 20 divisors (see below), whose sum is σ = 133049664. Its totient is φ = 57720600.

The previous prime is 87823511. The next prime is 87823523. The reversal of 87823521 is 12532878.

It is not a de Polignac number, because 87823521 - 2⁶ = 87823457 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (87823523) 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 19 ways as a sum of consecutive naturals, for example, 1885 + ... + 13386.

Almost surely, 2^87823521 is an apocalyptic number.

87823521 is a gapful number since it is divisible by the number (81) formed by its first and last digit.

It is an amenable number.

87823521 is a deficient number, since it is larger than the sum of its proper divisors (45226143).

87823521 is a wasteful number, since it uses less digits than its factorization.

87823521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15354 (or 15345 counting only the distinct ones).

The product of its digits is 26880, while the sum is 36.

The square root of 87823521 is about 9371.4204366254. The cubic root of 87823521 is about 444.4984814135.

The spelling of 87823521 in words is "eighty-seven million, eight hundred twenty-three thousand, five hundred twenty-one".