21843449 has 2 divisors, whose sum is σ = 21843450. Its totient is φ = 21843448.

The previous prime is 21843427. The next prime is 21843461. The reversal of 21843449 is 94434812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14115049 + 7728400 = 3757^2 + 2780^2 .

It is a cyclic number.

It is not a de Polignac number, because 21843449 - 2¹⁶ = 21777913 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21843649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10921724 + 10921725.

It is an arithmetic number, because the mean of its divisors is an integer number (10921725).

Almost surely, 2^21843449 is an apocalyptic number.

It is an amenable number.

21843449 is a deficient number, since it is larger than the sum of its proper divisors (1).

21843449 is an equidigital number, since it uses as much as digits as its factorization.

21843449 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27648, while the sum is 35.

The square root of 21843449 is about 4673.6975725864. The cubic root of 21843449 is about 279.5377108049.

The spelling of 21843449 in words is "twenty-one million, eight hundred forty-three thousand, four hundred forty-nine".