21113903 has 8 divisors (see below), whose sum is σ = 21698688. Its totient is φ = 20533464.

The previous prime is 21113887. The next prime is 21113927. The reversal of 21113903 is 30931112.

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

It is a cyclic number.

It is not a de Polignac number, because 21113903 - 2⁴ = 21113887 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 (21113933) by changing a digit.

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, 10376 + ... + 12242.

It is an arithmetic number, because the mean of its divisors is an integer number (2712336).

Almost surely, 2^21113903 is an apocalyptic number.

21113903 is a deficient number, since it is larger than the sum of its proper divisors (584785).

21113903 is a wasteful number, since it uses less digits than its factorization.

21113903 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2173.

The product of its (nonzero) digits is 162, while the sum is 20.

The square root of 21113903 is about 4594.9867246816. The cubic root of 21113903 is about 276.3903276187.

The spelling of 21113903 in words is "twenty-one million, one hundred thirteen thousand, nine hundred three".