21675285 has 12 divisors (see below), whose sum is σ = 37570572. Its totient is φ = 11560128.

The previous prime is 21675281. The next prime is 21675287. The reversal of 21675285 is 58257612.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 15944049 + 5731236 = 3993^2 + 2394^2 .

It is not a de Polignac number, because 21675285 - 2² = 21675281 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21675281) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 240792 + ... + 240881.

It is an arithmetic number, because the mean of its divisors is an integer number (3130881).

Almost surely, 2^21675285 is an apocalyptic number.

It is an amenable number.

21675285 is a deficient number, since it is larger than the sum of its proper divisors (15895287).

21675285 is a wasteful number, since it uses less digits than its factorization.

21675285 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 481684 (or 481681 counting only the distinct ones).

The product of its digits is 33600, while the sum is 36.

The square root of 21675285 is about 4655.6723467186. The cubic root of 21675285 is about 278.8185122538.

The spelling of 21675285 in words is "twenty-one million, six hundred seventy-five thousand, two hundred eighty-five".