43857921 has 8 divisors (see below), whose sum is σ = 58836640. Its totient is φ = 29058912.

The previous prime is 43857917. The next prime is 43857923. The reversal of 43857921 is 12975834.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 43857921 - 2² = 43857917 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 43857921.

It is not an unprimeable number, because it can be changed into a prime (43857923) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 44356 + ... + 45333.

It is an arithmetic number, because the mean of its divisors is an integer number (7354580).

Almost surely, 2^43857921 is an apocalyptic number.

It is an amenable number.

43857921 is a deficient number, since it is larger than the sum of its proper divisors (14978719).

43857921 is a wasteful number, since it uses less digits than its factorization.

43857921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89855.

The product of its digits is 60480, while the sum is 39.

The square root of 43857921 is about 6622.5313136293. The cubic root of 43857921 is about 352.6544326088.

The spelling of 43857921 in words is "forty-three million, eight hundred fifty-seven thousand, nine hundred twenty-one".