21084903 has 12 divisors (see below), whose sum is σ = 34806928. Its totient is φ = 12048480.

The previous prime is 21084887. The next prime is 21084923. The reversal of 21084903 is 30948012.

It is not a de Polignac number, because 21084903 - 2⁴ = 21084887 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 (21084923) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 167278 + ... + 167403.

Almost surely, 2^21084903 is an apocalyptic number.

21084903 is a deficient number, since it is larger than the sum of its proper divisors (13722025).

21084903 is a wasteful number, since it uses less digits than its factorization.

21084903 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 334694 (or 334691 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 21084903 is about 4591.8300273420. The cubic root of 21084903 is about 276.2637286981.

The spelling of 21084903 in words is "twenty-one million, eighty-four thousand, nine hundred three".