21028941 has 12 divisors (see below), whose sum is σ = 31116540. Its totient is φ = 13677120.

The previous prime is 21028939. The next prime is 21028979. The reversal of 21028941 is 14982012.

It can be written as a sum of positive squares in 2 ways, for example, as 9126441 + 11902500 = 3021^2 + 3450^2 .

It is not a de Polignac number, because 21028941 - 2¹ = 21028939 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21028901) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28126 + ... + 28863.

It is an arithmetic number, because the mean of its divisors is an integer number (2593045).

Almost surely, 2^21028941 is an apocalyptic number.

It is an amenable number.

21028941 is a deficient number, since it is larger than the sum of its proper divisors (10087599).

21028941 is a wasteful number, since it uses less digits than its factorization.

21028941 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57036 (or 57033 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 21028941 is about 4585.7323297375. The cubic root of 21028941 is about 276.0190991824.

The spelling of 21028941 in words is "twenty-one million, twenty-eight thousand, nine hundred forty-one".