43857006021 has 12 divisors (see below), whose sum is σ = 63401249548. Its totient is φ = 29213892864.

The previous prime is 43857006007. The next prime is 43857006023. The reversal of 43857006021 is 12060075834.

43857006021 is a `hidden beast` number, since 4 + 3 + 8 + 570 + 0 + 60 + 21 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 15602757921 + 28254248100 = 124911^2 + 168090^2 .

It is not a de Polignac number, because 43857006021 - 2⁷ = 43857005893 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 (43857006023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1997740 + ... + 2019573.

Almost surely, 2^43857006021 is an apocalyptic number.

It is an amenable number.

43857006021 is a deficient number, since it is larger than the sum of its proper divisors (19544243527).

43857006021 is a wasteful number, since it uses less digits than its factorization.

43857006021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4018532 (or 4018529 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

The spelling of 43857006021 in words is "forty-three billion, eight hundred fifty-seven million, six thousand, twenty-one".