21668933731593 has 4 divisors (see below), whose sum is σ = 28891911642128. Its totient is φ = 14445955821060.

The previous prime is 21668933731561. The next prime is 21668933731631. The reversal of 21668933731593 is 39513733986612.

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 not a de Polignac number, because 21668933731593 - 2⁵ = 21668933731561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21668933731493) 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, 3611488955263 + ... + 3611488955268.

It is an arithmetic number, because the mean of its divisors is an integer number (7222977910532).

Almost surely, 2^{21668933731593} is an apocalyptic number.

It is an amenable number.

21668933731593 is a deficient number, since it is larger than the sum of its proper divisors (7222977910535).

21668933731593 is an equidigital number, since it uses as much as digits as its factorization.

21668933731593 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7222977910534.

The product of its digits is 132269760, while the sum is 66.

The spelling of 21668933731593 in words is "twenty-one trillion, six hundred sixty-eight billion, nine hundred thirty-three million, seven hundred thirty-one thousand, five hundred ninety-three".