21810343 has 2 divisors, whose sum is σ = 21810344. Its totient is φ = 21810342.

The previous prime is 21810317. The next prime is 21810361. The reversal of 21810343 is 34301812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21810343 - 2⁵ = 21810311 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21813343) 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, 10905171 + 10905172.

It is an arithmetic number, because the mean of its divisors is an integer number (10905172).

Almost surely, 2^21810343 is an apocalyptic number.

21810343 is a deficient number, since it is larger than the sum of its proper divisors (1).

21810343 is an equidigital number, since it uses as much as digits as its factorization.

21810343 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 21810343 is about 4670.1544942325. The cubic root of 21810343 is about 279.3964166543.

The spelling of 21810343 in words is "twenty-one million, eight hundred ten thousand, three hundred forty-three".