27921 has 8 divisors (see below), whose sum is σ = 38304. Its totient is φ = 18080.

The previous prime is 27919. The next prime is 27941. The reversal of 27921 is 12972.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 27921 - 2¹ = 27919 is a prime.

It is a Curzon number.

It is a nialpdrome in base 8.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 27921.

It is not an unprimeable number, because it can be changed into a prime (27901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10 + ... + 236.

It is an arithmetic number, because the mean of its divisors is an integer number (4788).

2²⁷⁹²¹ is an apocalyptic number.

It is an amenable number.

27921 is a deficient number, since it is larger than the sum of its proper divisors (10383).

27921 is a wasteful number, since it uses less digits than its factorization.

27921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 271.

The product of its digits is 252, while the sum is 21.

The square root of 27921 is about 167.0957809162. The cubic root of 27921 is about 30.3373044218.

It can be divided in two parts, 279 and 21, that added together give a triangular number (300 = T₂₄).

The spelling of 27921 in words is "twenty-seven thousand, nine hundred twenty-one".