21744704417647 has 2 divisors, whose sum is σ = 21744704417648. Its totient is φ = 21744704417646.

The previous prime is 21744704417629. The next prime is 21744704417651. The reversal of 21744704417647 is 74671440744712.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21744704417647 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21744704417591 and 21744704417600.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21744704417147) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10872352208823 + 10872352208824.

It is an arithmetic number, because the mean of its divisors is an integer number (10872352208824).

Almost surely, 2^{21744704417647} is an apocalyptic number.

21744704417647 is a deficient number, since it is larger than the sum of its proper divisors (1).

21744704417647 is an equidigital number, since it uses as much as digits as its factorization.

21744704417647 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 29503488, while the sum is 58.

The spelling of 21744704417647 in words is "twenty-one trillion, seven hundred forty-four billion, seven hundred four million, four hundred seventeen thousand, six hundred forty-seven".