21201443984729 has 2 divisors, whose sum is σ = 21201443984730. Its totient is φ = 21201443984728.

The previous prime is 21201443984723. The next prime is 21201443984731. The reversal of 21201443984729 is 92748934410212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17024305106704 + 4177138878025 = 4126052^2 + 2043805^2 .

It is a cyclic number.

It is not a de Polignac number, because 21201443984729 - 2⁴⁰ = 20101932356953 is a prime.

Together with 21201443984731, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21201443984723) 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, 10600721992364 + 10600721992365.

It is an arithmetic number, because the mean of its divisors is an integer number (10600721992365).

Almost surely, 2^{21201443984729} is an apocalyptic number.

It is an amenable number.

21201443984729 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201443984729 is an equidigital number, since it uses as much as digits as its factorization.

21201443984729 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6967296, while the sum is 56.

The spelling of 21201443984729 in words is "twenty-one trillion, two hundred one billion, four hundred forty-three million, nine hundred eighty-four thousand, seven hundred twenty-nine".