21169903 has 8 divisors (see below), whose sum is σ = 21493440. Its totient is φ = 20848800.

The previous prime is 21169891. The next prime is 21169909. The reversal of 21169903 is 30996112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21169903 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21169909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23701 + ... + 24577.

It is an arithmetic number, because the mean of its divisors is an integer number (2686680).

Almost surely, 2^21169903 is an apocalyptic number.

21169903 is a deficient number, since it is larger than the sum of its proper divisors (323537).

21169903 is a wasteful number, since it uses less digits than its factorization.

21169903 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1217.

The product of its (nonzero) digits is 2916, while the sum is 31.

The square root of 21169903 is about 4601.0762871311. The cubic root of 21169903 is about 276.6344668256.

The spelling of 21169903 in words is "twenty-one million, one hundred sixty-nine thousand, nine hundred three".