33840 has 60 divisors (see below), whose sum is σ = 116064. Its totient is φ = 8832.

The previous prime is 33829. The next prime is 33851. The reversal of 33840 is 4833.

It is an interprime number because it is at equal distance from previous prime (33829) and next prime (33851).

It is a tau number, because it is divible by the number of its divisors (60).

It is a super-2 number, since 2×33840² = 2290291200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nialpdrome in base 16.

It is an unprimeable number.

33840 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 697 + ... + 743.

2³³⁸⁴⁰ is an apocalyptic number.

33840 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 33840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (58032).

33840 is an abundant number, since it is smaller than the sum of its proper divisors (82224).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

33840 is a wasteful number, since it uses less digits than its factorization.

33840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66 (or 57 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 33840 is about 183.9565166011. The cubic root of 33840 is about 32.3452206501.

It can be divided in two parts, 338 and 40, that added together give a triangular number (378 = T₂₇).

The spelling of 33840 in words is "thirty-three thousand, eight hundred forty".