21303875 has 16 divisors (see below), whose sum is σ = 26810784. Its totient is φ = 16900000.

The previous prime is 21303857. The next prime is 21303901. The reversal of 21303875 is 57830312.

It is not a de Polignac number, because 21303875 - 2¹⁸ = 21041731 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15725 + ... + 17025.

It is an arithmetic number, because the mean of its divisors is an integer number (1675674).

Almost surely, 2^21303875 is an apocalyptic number.

21303875 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21303875 is a deficient number, since it is larger than the sum of its proper divisors (5506909).

21303875 is a wasteful number, since it uses less digits than its factorization.

21303875 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1447 (or 1437 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 21303875 is about 4615.6120937531. The cubic root of 21303875 is about 277.2167930138.

The spelling of 21303875 in words is "twenty-one million, three hundred three thousand, eight hundred seventy-five".