40643 has 4 divisors (see below), whose sum is σ = 41160.
Its totient is φ = 40128.
The previous prime is 40639. The next prime is 40693. The reversal of 40643 is 34604.
It is a semiprime because it is the product of two primes.
It is a cyclic number.
It is not a de Polignac number, because 40643 - 22 = 40639 is a prime.
It is a Duffinian number.
It is not an unprimeable number, because it can be changed into a prime (40693) by changing a digit.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 113 + ... + 306.
It is an arithmetic number, because the mean of its divisors is an integer number (10290).
240643 is an apocalyptic number.
40643 is a deficient number, since it is larger than the sum of its proper divisors (517).
40643 is an equidigital number, since it uses as much as digits as its factorization.
40643 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 516.
The product of its (nonzero) digits is 288, while the sum is 17.
The square root of 40643 is about 201.6010912669.
The cubic root of 40643 is about 34.3817981045.
The spelling of 40643 in words is "forty thousand, six hundred forty-three".