21872203 has 2 divisors, whose sum is σ = 21872204. Its totient is φ = 21872202.

The previous prime is 21872171. The next prime is 21872209. The reversal of 21872203 is 30227812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21872203 - 2⁵ = 21872171 is a prime.

It is not a weakly prime, because it can be changed into another prime (21872209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10936101 + 10936102.

It is an arithmetic number, because the mean of its divisors is an integer number (10936102).

Almost surely, 2^21872203 is an apocalyptic number.

21872203 is a deficient number, since it is larger than the sum of its proper divisors (1).

21872203 is an equidigital number, since it uses as much as digits as its factorization.

21872203 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 21872203 is about 4676.7727120312. The cubic root of 21872203 is about 279.6603151152.

The spelling of 21872203 in words is "twenty-one million, eight hundred seventy-two thousand, two hundred three".