21456203 has 2 divisors, whose sum is σ = 21456204. Its totient is φ = 21456202.

The previous prime is 21456199. The next prime is 21456221. The reversal of 21456203 is 30265412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21456203 - 2² = 21456199 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (21456103) 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 as a sum of consecutive naturals, namely, 10728101 + 10728102.

It is an arithmetic number, because the mean of its divisors is an integer number (10728102).

Almost surely, 2^21456203 is an apocalyptic number.

21456203 is a deficient number, since it is larger than the sum of its proper divisors (1).

21456203 is an equidigital number, since it uses as much as digits as its factorization.

21456203 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 21456203 is about 4632.0840881832. The cubic root of 21456203 is about 277.8759474469.

The spelling of 21456203 in words is "twenty-one million, four hundred fifty-six thousand, two hundred three".