43255564021 has 2 divisors, whose sum is σ = 43255564022. Its totient is φ = 43255564020.

The previous prime is 43255564019. The next prime is 43255564043. The reversal of 43255564021 is 12046555234.

43255564021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23038989796 + 20216574225 = 151786^2 + 142185^2 .

It is a cyclic number.

It is not a de Polignac number, because 43255564021 - 2¹ = 43255564019 is a prime.

Together with 43255564019, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43255564081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21627782010 + 21627782011.

It is an arithmetic number, because the mean of its divisors is an integer number (21627782011).

Almost surely, 2^43255564021 is an apocalyptic number.

It is an amenable number.

43255564021 is a deficient number, since it is larger than the sum of its proper divisors (1).

43255564021 is an equidigital number, since it uses as much as digits as its factorization.

43255564021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144000, while the sum is 37.

The spelling of 43255564021 in words is "forty-three billion, two hundred fifty-five million, five hundred sixty-four thousand, twenty-one".