43541021 has 2 divisors, whose sum is σ = 43541022. Its totient is φ = 43541020.

The previous prime is 43541009. The next prime is 43541023. The reversal of 43541021 is 12014534.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 35868121 + 7672900 = 5989^2 + 2770^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-43541021 is a prime.

It is a Sophie Germain prime.

Together with 43541023, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 43540984 and 43541002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43541023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21770510 + 21770511.

It is an arithmetic number, because the mean of its divisors is an integer number (21770511).

Almost surely, 2^43541021 is an apocalyptic number.

It is an amenable number.

43541021 is a deficient number, since it is larger than the sum of its proper divisors (1).

43541021 is an equidigital number, since it uses as much as digits as its factorization.

43541021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 43541021 is about 6598.5620403236. The cubic root of 43541021 is about 351.8029980860.

Adding to 43541021 its reverse (12014534), we get a palindrome (55555555).

The spelling of 43541021 in words is "forty-three million, five hundred forty-one thousand, twenty-one".