21744704417721 has 16 divisors (see below), whose sum is σ = 29928403845120. Its totient is φ = 14028743817360.

The previous prime is 21744704417699. The next prime is 21744704417743. The reversal of 21744704417721 is 12771440744712.

It is an interprime number because it is at equal distance from previous prime (21744704417699) and next prime (21744704417743).

It is not a de Polignac number, because 21744704417721 - 2¹⁰ = 21744704416697 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21744704417771) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14057496 + ... + 15527478.

It is an arithmetic number, because the mean of its divisors is an integer number (1870525240320).

Almost surely, 2^{21744704417721} is an apocalyptic number.

It is an amenable number.

21744704417721 is a deficient number, since it is larger than the sum of its proper divisors (8183699427399).

21744704417721 is a wasteful number, since it uses less digits than its factorization.

21744704417721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1629076.

The product of its (nonzero) digits is 2458624, while the sum is 51.

The spelling of 21744704417721 in words is "twenty-one trillion, seven hundred forty-four billion, seven hundred four million, four hundred seventeen thousand, seven hundred twenty-one".