99684521 has 4 divisors (see below), whose sum is σ = 99970500. Its totient is φ = 99398544.

The previous prime is 99684511. The next prime is 99684551. The reversal of 99684521 is 12548699.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 78570496 + 21114025 = 8864^2 + 4595^2 .

It is a cyclic number.

It is not a de Polignac number, because 99684521 - 2⁶ = 99684457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99684511) 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, 142466 + ... + 143163.

It is an arithmetic number, because the mean of its divisors is an integer number (24992625).

Almost surely, 2^99684521 is an apocalyptic number.

It is an amenable number.

99684521 is a deficient number, since it is larger than the sum of its proper divisors (285979).

99684521 is a wasteful number, since it uses less digits than its factorization.

99684521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 285978.

The product of its digits is 155520, while the sum is 44.

The square root of 99684521 is about 9984.2135894621. The cubic root of 99684521 is about 463.6702612325.

The spelling of 99684521 in words is "ninety-nine million, six hundred eighty-four thousand, five hundred twenty-one".