31965 has 8 divisors (see below), whose sum is σ = 51168. Its totient is φ = 17040.

The previous prime is 31963. The next prime is 31973. The reversal of 31965 is 56913.

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

It is not a de Polignac number, because 31965 - 2¹ = 31963 is a prime.

It is a super-2 number, since 2×31965² = 2043522450, which contains 22 as substring.

31965 is a lucky number.

It is a plaindrome in base 16.

It is a nialpdrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31963) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1051 + ... + 1080.

It is an arithmetic number, because the mean of its divisors is an integer number (6396).

2³¹⁹⁶⁵ is an apocalyptic number.

It is an amenable number.

31965 is a deficient number, since it is larger than the sum of its proper divisors (19203).

31965 is a wasteful number, since it uses less digits than its factorization.

31965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2139.

The product of its digits is 810, while the sum is 24.

The square root of 31965 is about 178.7875834615. The cubic root of 31965 is about 31.7364420175.

The spelling of 31965 in words is "thirty-one thousand, nine hundred sixty-five".