43857421 has 4 divisors (see below), whose sum is σ = 44039644. Its totient is φ = 43675200.

The previous prime is 43857409. The next prime is 43857427. The reversal of 43857421 is 12475834.

43857421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 30680521 + 13176900 = 5539^2 + 3630^2 .

It is a cyclic number.

It is not a de Polignac number, because 43857421 - 2⁷ = 43857293 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43857427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 90750 + ... + 91231.

It is an arithmetic number, because the mean of its divisors is an integer number (11009911).

Almost surely, 2^43857421 is an apocalyptic number.

It is an amenable number.

43857421 is a deficient number, since it is larger than the sum of its proper divisors (182223).

43857421 is a wasteful number, since it uses less digits than its factorization.

43857421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182222.

The product of its digits is 26880, while the sum is 34.

The square root of 43857421 is about 6622.4935636058. The cubic root of 43857421 is about 352.6530924641.

The spelling of 43857421 in words is "forty-three million, eight hundred fifty-seven thousand, four hundred twenty-one".