21921203 has 4 divisors (see below), whose sum is σ = 21947640. Its totient is φ = 21894768.

The previous prime is 21921191. The next prime is 21921227. The reversal of 21921203 is 30212912.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21921203 - 2¹⁰ = 21920179 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21921253) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11933 + ... + 13646.

It is an arithmetic number, because the mean of its divisors is an integer number (5486910).

Almost surely, 2^21921203 is an apocalyptic number.

21921203 is a deficient number, since it is larger than the sum of its proper divisors (26437).

21921203 is an equidigital number, since it uses as much as digits as its factorization.

21921203 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26436.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 21921203 is about 4682.0084365580. The cubic root of 21921203 is about 279.8689990936.

The spelling of 21921203 in words is "twenty-one million, nine hundred twenty-one thousand, two hundred three".