21066049 has 2 divisors, whose sum is σ = 21066050. Its totient is φ = 21066048.

The previous prime is 21066013. The next prime is 21066107. The reversal of 21066049 is 94066012.

21066049 is nontrivially palindromic in base 16.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20930625 + 135424 = 4575^2 + 368^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21066049 is a prime.

It is not a weakly prime, because it can be changed into another prime (21066449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10533024 + 10533025.

It is an arithmetic number, because the mean of its divisors is an integer number (10533025).

Almost surely, 2^21066049 is an apocalyptic number.

It is an amenable number.

21066049 is a deficient number, since it is larger than the sum of its proper divisors (1).

21066049 is an equidigital number, since it uses as much as digits as its factorization.

21066049 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 21066049 is about 4589.7765740829. The cubic root of 21066049 is about 276.1813596584.

The spelling of 21066049 in words is "twenty-one million, sixty-six thousand, forty-nine".