21791935771 has 4 divisors (see below), whose sum is σ = 21792366232. Its totient is φ = 21791505312.

The previous prime is 21791935733. The next prime is 21791935793. The reversal of 21791935771 is 17753919712.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21791935771 - 2³¹ = 19644452123 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21791935171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 127326 + ... + 244531.

It is an arithmetic number, because the mean of its divisors is an integer number (5448091558).

Almost surely, 2^21791935771 is an apocalyptic number.

21791935771 is a deficient number, since it is larger than the sum of its proper divisors (430461).

21791935771 is an equidigital number, since it uses as much as digits as its factorization.

21791935771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430460.

The product of its digits is 833490, while the sum is 52.

The spelling of 21791935771 in words is "twenty-one billion, seven hundred ninety-one million, nine hundred thirty-five thousand, seven hundred seventy-one".