21936827171 has 4 divisors (see below), whose sum is σ = 25070659632. Its totient is φ = 18802994712.

The previous prime is 21936827167. The next prime is 21936827179. The reversal of 21936827171 is 17172863912.

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 21936827171 - 2² = 21936827167 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21936827179) 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, 1566916220 + ... + 1566916233.

It is an arithmetic number, because the mean of its divisors is an integer number (6267664908).

Almost surely, 2^21936827171 is an apocalyptic number.

21936827171 is a deficient number, since it is larger than the sum of its proper divisors (3133832461).

21936827171 is an equidigital number, since it uses as much as digits as its factorization.

21936827171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3133832460.

The product of its digits is 254016, while the sum is 47.

The spelling of 21936827171 in words is "twenty-one billion, nine hundred thirty-six million, eight hundred twenty-seven thousand, one hundred seventy-one".