21184085 has 16 divisors (see below), whose sum is σ = 28047600. Its totient is φ = 15260160.

The previous prime is 21184073. The next prime is 21184099. The reversal of 21184085 is 58048112.

It can be written as a sum of positive squares in 8 ways, for example, as 5958481 + 15225604 = 2441^2 + 3902^2 .

It is not a de Polignac number, because 21184085 - 2⁸ = 21183829 is a prime.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 1310 + ... + 6639.

It is an arithmetic number, because the mean of its divisors is an integer number (1752975).

Almost surely, 2^21184085 is an apocalyptic number.

It is an amenable number.

21184085 is a deficient number, since it is larger than the sum of its proper divisors (6863515).

21184085 is a wasteful number, since it uses less digits than its factorization.

21184085 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8008.

The product of its (nonzero) digits is 2560, while the sum is 29.

The square root of 21184085 is about 4602.6171902517. The cubic root of 21184085 is about 276.6962267411.

The spelling of 21184085 in words is "twenty-one million, one hundred eighty-four thousand, eighty-five".