27931 has 8 divisors (see below), whose sum is σ = 31104. Its totient is φ = 24960.

The previous prime is 27919. The next prime is 27941. The reversal of 27931 is 13972.

27931 = T₂₆ + T₂₇ + ... + T₅₆.

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 27931 - 2⁷ = 27803 is a prime.

It is a super-2 number, since 2×27931² = 1560281522, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 8 and base 15.

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

It is a nontrivial repunit in base 30.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 501 + ... + 553.

It is an arithmetic number, because the mean of its divisors is an integer number (3888).

2²⁷⁹³¹ is an apocalyptic number.

27931 is the 106-th heptagonal number.

27931 is a deficient number, since it is larger than the sum of its proper divisors (3173).

27931 is a wasteful number, since it uses less digits than its factorization.

27931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101.

The product of its digits is 378, while the sum is 22.

The square root of 27931 is about 167.1257011952. The cubic root of 27931 is about 30.3409257920.

It can be divided in two parts, 279 and 31, that multiplied together give a square (8649 = 93²).

The spelling of 27931 in words is "twenty-seven thousand, nine hundred thirty-one".