21028214 has 8 divisors (see below), whose sum is σ = 31673928. Its totient is φ = 10470240.

The previous prime is 21028213. The next prime is 21028229. The reversal of 21028214 is 41282012.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21028211) 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 3 ways as a sum of consecutive naturals, for example, 21332 + ... + 22295.

It is an arithmetic number, because the mean of its divisors is an integer number (3959241).

Almost surely, 2^21028214 is an apocalyptic number.

21028214 is a deficient number, since it is larger than the sum of its proper divisors (10645714).

21028214 is a wasteful number, since it uses less digits than its factorization.

21028214 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43870.

The product of its (nonzero) digits is 256, while the sum is 20.

The square root of 21028214 is about 4585.6530614516. The cubic root of 21028214 is about 276.0159183566.

The spelling of 21028214 in words is "twenty-one million, twenty-eight thousand, two hundred fourteen".