27171895921 has 3 divisors (see below), whose sum is σ = 27172060761. Its totient is φ = 27171731082.

The previous prime is 27171895913. The next prime is 27171895967. The reversal of 27171895921 is 12959817172.

The square root of 27171895921 is 164839.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 27171895921 - 2³ = 27171895913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27171893921) 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 2 ways as a sum of consecutive naturals, for example, 82420 + ... + 247258.

It is an arithmetic number, because the mean of its divisors is an integer number (9057353587).

Almost surely, 2^27171895921 is an apocalyptic number.

27171895921 is the 164839-th square number.

27171895921 is the 82420-th centered octagonal number.

It is an amenable number.

27171895921 is a deficient number, since it is larger than the sum of its proper divisors (164840).

27171895921 is an frugal number, since it uses more digits than its factorization.

27171895921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 329678 (or 164839 counting only the distinct ones).

The product of its digits is 635040, while the sum is 52.

The spelling of 27171895921 in words is "twenty-seven billion, one hundred seventy-one million, eight hundred ninety-five thousand, nine hundred twenty-one".