21303075 has 12 divisors (see below), whose sum is σ = 35221208. Its totient is φ = 11361600.

The previous prime is 21303059. The next prime is 21303109. The reversal of 21303075 is 57030312.

It is a happy number.

It is not a de Polignac number, because 21303075 - 2⁴ = 21303059 is a prime.

It is a Duffinian number.

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 11 ways as a sum of consecutive naturals, for example, 141946 + ... + 142095.

Almost surely, 2^21303075 is an apocalyptic number.

21303075 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21303075 is a deficient number, since it is larger than the sum of its proper divisors (13918133).

21303075 is a wasteful number, since it uses less digits than its factorization.

21303075 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 284054 (or 284049 counting only the distinct ones).

The product of its (nonzero) digits is 630, while the sum is 21.

The square root of 21303075 is about 4615.5254305442. The cubic root of 21303075 is about 277.2133229689.

Adding to 21303075 its reverse (57030312), we get a palindrome (78333387).

It can be divided in two parts, 2130307 and 5, that added together give a palindrome (2130312).

The spelling of 21303075 in words is "twenty-one million, three hundred three thousand, seventy-five".