43640 has 16 divisors (see below), whose sum is σ = 98280. Its totient is φ = 17440.

The previous prime is 43633. The next prime is 43649. The reversal of 43640 is 4634.

43640 is nontrivially palindromic in base 7.

43640 is digitally balanced in base 2 and base 6, because in such bases it contains all the possibile digits an equal number of times.

43640 is strictly pandigital in base 6.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43649) by changing a digit.

43640 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, 506 + ... + 585.

2⁴³⁶⁴⁰ is an apocalyptic number.

43640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

43640 is an abundant number, since it is smaller than the sum of its proper divisors (54640).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49140).

43640 is a wasteful number, since it uses less digits than its factorization.

43640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1102 (or 1098 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 17.

The square root of 43640 is about 208.9018908483. The cubic root of 43640 is about 35.2069373379.

The spelling of 43640 in words is "forty-three thousand, six hundred forty".