21442903 has 8 divisors (see below), whose sum is σ = 21943040. Its totient is φ = 20947680.

The previous prime is 21442871. The next prime is 21442913. The reversal of 21442903 is 30924412.

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 21442903 - 2⁵ = 21442871 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 (21442913) 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, 8458 + ... + 10696.

It is an arithmetic number, because the mean of its divisors is an integer number (2742880).

Almost surely, 2^21442903 is an apocalyptic number.

21442903 is a deficient number, since it is larger than the sum of its proper divisors (500137).

21442903 is a wasteful number, since it uses less digits than its factorization.

21442903 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2457.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 21442903 is about 4630.6482267605. The cubic root of 21442903 is about 277.8185201691.

The spelling of 21442903 in words is "twenty-one million, four hundred forty-two thousand, nine hundred three".