43821641 has 2 divisors, whose sum is σ = 43821642. Its totient is φ = 43821640.

The previous prime is 43821637. The next prime is 43821667. The reversal of 43821641 is 14612834.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39639616 + 4182025 = 6296^2 + 2045^2 .

It is a cyclic number.

It is not a de Polignac number, because 43821641 - 2² = 43821637 is a prime.

It is a Chen prime.

It is equal to p_2651186 and since 43821641 and 2651186 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (43821671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21910820 + 21910821.

It is an arithmetic number, because the mean of its divisors is an integer number (21910821).

Almost surely, 2^43821641 is an apocalyptic number.

It is an amenable number.

43821641 is a deficient number, since it is larger than the sum of its proper divisors (1).

43821641 is an equidigital number, since it uses as much as digits as its factorization.

43821641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4608, while the sum is 29.

The square root of 43821641 is about 6619.7916130344. The cubic root of 43821641 is about 352.5571652507.

The spelling of 43821641 in words is "forty-three million, eight hundred twenty-one thousand, six hundred forty-one".