21075685 has 8 divisors (see below), whose sum is σ = 25719840. Its totient is φ = 16574544.

The previous prime is 21075679. The next prime is 21075689. The reversal of 21075685 is 58657012.

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

It is a cyclic number.

It is not a de Polignac number, because 21075685 - 2⁵ = 21075653 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21075685.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21075689) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35427 + ... + 36016.

It is an arithmetic number, because the mean of its divisors is an integer number (3214980).

Almost surely, 2^21075685 is an apocalyptic number.

It is an amenable number.

21075685 is a deficient number, since it is larger than the sum of its proper divisors (4644155).

21075685 is an equidigital number, since it uses as much as digits as its factorization.

21075685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71507.

The product of its (nonzero) digits is 16800, while the sum is 34.

The square root of 21075685 is about 4590.8261783692. The cubic root of 21075685 is about 276.2234633915.

The spelling of 21075685 in words is "twenty-one million, seventy-five thousand, six hundred eighty-five".