21075284 has 12 divisors (see below), whose sum is σ = 37048704. Its totient is φ = 10489944.

The previous prime is 21075283. The next prime is 21075347. The reversal of 21075284 is 48257012.

It is a hoax number, since the sum of its digits (29) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21075283) 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, 10922 + ... + 12705.

It is an arithmetic number, because the mean of its divisors is an integer number (3087392).

Almost surely, 2^21075284 is an apocalyptic number.

It is an amenable number.

21075284 is a deficient number, since it is larger than the sum of its proper divisors (15973420).

21075284 is a wasteful number, since it uses less digits than its factorization.

21075284 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23854 (or 23852 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 29.

The square root of 21075284 is about 4590.7825041054. The cubic root of 21075284 is about 276.2217115099.

The spelling of 21075284 in words is "twenty-one million, seventy-five thousand, two hundred eighty-four".