21223903 has 16 divisors (see below), whose sum is σ = 22654080. Its totient is φ = 19858176.

The previous prime is 21223901. The next prime is 21223927. The reversal of 21223903 is 30932212.

It is a cyclic number.

It is not a de Polignac number, because 21223903 - 2¹ = 21223901 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 (21223901) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 154851 + ... + 154987.

It is an arithmetic number, because the mean of its divisors is an integer number (1415880).

Almost surely, 2^21223903 is an apocalyptic number.

21223903 is a deficient number, since it is larger than the sum of its proper divisors (1430177).

21223903 is a wasteful number, since it uses less digits than its factorization.

21223903 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 306.

The product of its (nonzero) digits is 648, while the sum is 22.

The square root of 21223903 is about 4606.9407419675. The cubic root of 21223903 is about 276.8694793607.

The spelling of 21223903 in words is "twenty-one million, two hundred twenty-three thousand, nine hundred three".