21120903 has 12 divisors (see below), whose sum is σ = 31560360. Its totient is φ = 13594896.

The previous prime is 21120901. The next prime is 21120929. The reversal of 21120903 is 30902112.

It is a happy number.

It is not a de Polignac number, because 21120903 - 2¹ = 21120901 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120901) 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 11 ways as a sum of consecutive naturals, for example, 40201 + ... + 40722.

It is an arithmetic number, because the mean of its divisors is an integer number (2630030).

Almost surely, 2^21120903 is an apocalyptic number.

21120903 is a deficient number, since it is larger than the sum of its proper divisors (10439457).

21120903 is a wasteful number, since it uses less digits than its factorization.

21120903 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80958 (or 80955 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

The square root of 21120903 is about 4595.7483612574. The cubic root of 21120903 is about 276.4208686091.

The spelling of 21120903 in words is "twenty-one million, one hundred twenty thousand, nine hundred three".