21752865199617 has 4 divisors (see below), whose sum is σ = 29003820266160. Its totient is φ = 14501910133076.

The previous prime is 21752865199613. The next prime is 21752865199657. The reversal of 21752865199617 is 71699156825712.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21752865199617 - 2² = 21752865199613 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21752865199613) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3625477533267 + ... + 3625477533272.

It is an arithmetic number, because the mean of its divisors is an integer number (7250955066540).

Almost surely, 2^{21752865199617} is an apocalyptic number.

It is an amenable number.

21752865199617 is a deficient number, since it is larger than the sum of its proper divisors (7250955066543).

21752865199617 is an equidigital number, since it uses as much as digits as its factorization.

21752865199617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7250955066542.

The product of its digits is 114307200, while the sum is 69.

The spelling of 21752865199617 in words is "twenty-one trillion, seven hundred fifty-two billion, eight hundred sixty-five million, one hundred ninety-nine thousand, six hundred seventeen".