21030730 has 16 divisors (see below), whose sum is σ = 43263360. Its totient is φ = 7210512.

The previous prime is 21030721. The next prime is 21030767. The reversal of 21030730 is 3703012.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 150150 + ... + 150289.

It is an arithmetic number, because the mean of its divisors is an integer number (2703960).

Almost surely, 2^21030730 is an apocalyptic number.

21030730 is an abundant number, since it is smaller than the sum of its proper divisors (22232630).

21030730 is a wasteful number, since it uses less digits than its factorization.

21030730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300453.

The product of its (nonzero) digits is 126, while the sum is 16.

The square root of 21030730 is about 4585.9273871268. The cubic root of 21030730 is about 276.0269262395.

Adding to 21030730 its reverse (3703012), we get a palindrome (24733742).

The spelling of 21030730 in words is "twenty-one million, thirty thousand, seven hundred thirty".