43904 has 32 divisors (see below), whose sum is σ = 102000. Its totient is φ = 18816.

The previous prime is 43891. The next prime is 43913. The reversal of 43904 is 40934.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It is a tau number, because it is divible by the number of its divisors (32).

It is a super-2 number, since 2×43904² = 3855122432, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

43904 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 3 ways as a sum of consecutive naturals, for example, 6269 + ... + 6275.

2⁴³⁹⁰⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 43904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51000).

43904 is an abundant number, since it is smaller than the sum of its proper divisors (58096).

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

43904 is an frugal number, since it uses more digits than its factorization.

43904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35 (or 9 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 43904 is about 209.5328136593. The cubic root of 43904 is about 35.2777893971.

The spelling of 43904 in words is "forty-three thousand, nine hundred four".