21704833 has 2 divisors, whose sum is σ = 21704834. Its totient is φ = 21704832.

The previous prime is 21704831. The next prime is 21704857. The reversal of 21704833 is 33840712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21594609 + 110224 = 4647^2 + 332^2 .

It is a cyclic number.

It is not a de Polignac number, because 21704833 - 2¹ = 21704831 is a prime.

Together with 21704831, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21704831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10852416 + 10852417.

It is an arithmetic number, because the mean of its divisors is an integer number (10852417).

Almost surely, 2^21704833 is an apocalyptic number.

It is an amenable number.

21704833 is a deficient number, since it is larger than the sum of its proper divisors (1).

21704833 is an equidigital number, since it uses as much as digits as its factorization.

21704833 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 21704833 is about 4658.8445992542. The cubic root of 21704833 is about 278.9451509364.

It can be divided in two parts, 2170483 and 3, that added together give a triangular number (2170486 = T₂₀₈₃).

The spelling of 21704833 in words is "twenty-one million, seven hundred four thousand, eight hundred thirty-three".