43455821 has 2 divisors, whose sum is σ = 43455822. Its totient is φ = 43455820.

The previous prime is 43455817. The next prime is 43455823. The reversal of 43455821 is 12855434.

43455821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25908100 + 17547721 = 5090^2 + 4189^2 .

It is a cyclic number.

It is not a de Polignac number, because 43455821 - 2² = 43455817 is a prime.

Together with 43455823, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43455823) 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 as a sum of consecutive naturals, namely, 21727910 + 21727911.

It is an arithmetic number, because the mean of its divisors is an integer number (21727911).

Almost surely, 2^43455821 is an apocalyptic number.

It is an amenable number.

43455821 is a deficient number, since it is larger than the sum of its proper divisors (1).

43455821 is an equidigital number, since it uses as much as digits as its factorization.

43455821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 19200, while the sum is 32.

The square root of 43455821 is about 6592.1029269877. The cubic root of 43455821 is about 351.5733817642.

The spelling of 43455821 in words is "forty-three million, four hundred fifty-five thousand, eight hundred twenty-one".