21044129 has 2 divisors, whose sum is σ = 21044130. Its totient is φ = 21044128.

The previous prime is 21044117. The next prime is 21044197. The reversal of 21044129 is 92144012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21022225 + 21904 = 4585^2 + 148^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21044129 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21043129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10522064 + 10522065.

It is an arithmetic number, because the mean of its divisors is an integer number (10522065).

Almost surely, 2^21044129 is an apocalyptic number.

It is an amenable number.

21044129 is a deficient number, since it is larger than the sum of its proper divisors (1).

21044129 is an equidigital number, since it uses as much as digits as its factorization.

21044129 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 21044129 is about 4587.3880367808. The cubic root of 21044129 is about 276.0855341212.

The spelling of 21044129 in words is "twenty-one million, forty-four thousand, one hundred twenty-nine".