21030284 has 18 divisors (see below), whose sum is σ = 40453812. Its totient is φ = 9559000.

The previous prime is 21030239. The next prime is 21030287. The reversal of 21030284 is 48203012.

It is not an unprimeable number, because it can be changed into a prime (21030287) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 21242 + ... + 22209.

It is an arithmetic number, because the mean of its divisors is an integer number (2247434).

Almost surely, 2^21030284 is an apocalyptic number.

It is an amenable number.

21030284 is a deficient number, since it is larger than the sum of its proper divisors (19423528).

21030284 is a wasteful number, since it uses less digits than its factorization.

21030284 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43477 (or 43464 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 21030284 is about 4585.8787598453. The cubic root of 21030284 is about 276.0249749856.

Adding to 21030284 its reverse (48203012), we get a palindrome (69233296).

The spelling of 21030284 in words is "twenty-one million, thirty thousand, two hundred eighty-four".