21724303 has 2 divisors, whose sum is σ = 21724304. Its totient is φ = 21724302.

The previous prime is 21724271. The next prime is 21724309. The reversal of 21724303 is 30342712.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21724303 - 2⁵ = 21724271 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21724309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10862151 + 10862152.

It is an arithmetic number, because the mean of its divisors is an integer number (10862152).

Almost surely, 2^21724303 is an apocalyptic number.

21724303 is a deficient number, since it is larger than the sum of its proper divisors (1).

21724303 is an equidigital number, since it uses as much as digits as its factorization.

21724303 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1008, while the sum is 22.

The square root of 21724303 is about 4660.9337047420. The cubic root of 21724303 is about 279.0285338853.

The spelling of 21724303 in words is "twenty-one million, seven hundred twenty-four thousand, three hundred three".