21441401309 has 2 divisors, whose sum is σ = 21441401310. Its totient is φ = 21441401308.

The previous prime is 21441401213. The next prime is 21441401341. The reversal of 21441401309 is 90310414412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17389696900 + 4051704409 = 131870^2 + 63653^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21441401309 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21441401209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10720700654 + 10720700655.

It is an arithmetic number, because the mean of its divisors is an integer number (10720700655).

Almost surely, 2^21441401309 is an apocalyptic number.

It is an amenable number.

21441401309 is a deficient number, since it is larger than the sum of its proper divisors (1).

21441401309 is an equidigital number, since it uses as much as digits as its factorization.

21441401309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 29.

The spelling of 21441401309 in words is "twenty-one billion, four hundred forty-one million, four hundred one thousand, three hundred nine".