43812 has 18 divisors (see below), whose sum is σ = 110838. Its totient is φ = 14592.

The previous prime is 43801. The next prime is 43853. The reversal of 43812 is 21834.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 34596 + 9216 = 186^2 + 96^2 .

It is a tau number, because it is divible by the number of its divisors (18).

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

It is an Ulam number.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is an unprimeable number.

43812 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 5 ways as a sum of consecutive naturals, for example, 573 + ... + 644.

2⁴³⁸¹² is an apocalyptic number.

It is an amenable number.

43812 is an abundant number, since it is smaller than the sum of its proper divisors (67026).

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

43812 is a wasteful number, since it uses less digits than its factorization.

43812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1227 (or 1222 counting only the distinct ones).

The product of its digits is 192, while the sum is 18.

The square root of 43812 is about 209.3131625101. The cubic root of 43812 is about 35.2531308521.

The spelling of 43812 in words is "forty-three thousand, eight hundred twelve".