21424049 has 2 divisors, whose sum is σ = 21424050. Its totient is φ = 21424048.

The previous prime is 21424027. The next prime is 21424061. The reversal of 21424049 is 94042412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11343424 + 10080625 = 3368^2 + 3175^2 .

It is a cyclic number.

It is not a de Polignac number, because 21424049 - 2⁸ = 21423793 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21424079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10712024 + 10712025.

It is an arithmetic number, because the mean of its divisors is an integer number (10712025).

Almost surely, 2^21424049 is an apocalyptic number.

It is an amenable number.

21424049 is a deficient number, since it is larger than the sum of its proper divisors (1).

21424049 is an equidigital number, since it uses as much as digits as its factorization.

21424049 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 21424049 is about 4628.6119949721. The cubic root of 21424049 is about 277.7370709001.

The spelling of 21424049 in words is "twenty-one million, four hundred twenty-four thousand, forty-nine".