21188085 has 8 divisors (see below), whose sum is σ = 33900960. Its totient is φ = 11300304.

The previous prime is 21188053. The next prime is 21188093. The reversal of 21188085 is 58088112.

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

It is not a de Polignac number, because 21188085 - 2⁵ = 21188053 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 706255 + ... + 706284.

It is an arithmetic number, because the mean of its divisors is an integer number (4237620).

Almost surely, 2^21188085 is an apocalyptic number.

It is an amenable number.

21188085 is a deficient number, since it is larger than the sum of its proper divisors (12712875).

21188085 is a wasteful number, since it uses less digits than its factorization.

21188085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1412547.

The product of its (nonzero) digits is 5120, while the sum is 33.

The square root of 21188085 is about 4603.0517051191. The cubic root of 21188085 is about 276.7136409973.

The spelling of 21188085 in words is "twenty-one million, one hundred eighty-eight thousand, eighty-five".