21030436 has 12 divisors (see below), whose sum is σ = 42060928. Its totient is φ = 9013032.

The previous prime is 21030403. The next prime is 21030463. The reversal of 21030436 is 63403012.

21030436 is an admirable number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 375516 + ... + 375571.

Almost surely, 2^21030436 is an apocalyptic number.

It is an amenable number.

21030436 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21030436 is a wasteful number, since it uses less digits than its factorization.

21030436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 751098 (or 751096 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 19.

The square root of 21030436 is about 4585.8953324296. The cubic root of 21030436 is about 276.0256399901.

Adding to 21030436 its reverse (63403012), we get a palindrome (84433448).

The spelling of 21030436 in words is "twenty-one million, thirty thousand, four hundred thirty-six".