43649861 has 2 divisors, whose sum is σ = 43649862. Its totient is φ = 43649860.

The previous prime is 43649857. The next prime is 43649867. The reversal of 43649861 is 16894634.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27888961 + 15760900 = 5281^2 + 3970^2 .

It is a cyclic number.

It is not a de Polignac number, because 43649861 - 2² = 43649857 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43649867) 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, 21824930 + 21824931.

It is an arithmetic number, because the mean of its divisors is an integer number (21824931).

Almost surely, 2^43649861 is an apocalyptic number.

It is an amenable number.

43649861 is a deficient number, since it is larger than the sum of its proper divisors (1).

43649861 is an equidigital number, since it uses as much as digits as its factorization.

43649861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 124416, while the sum is 41.

The square root of 43649861 is about 6606.8041442138. The cubic root of 43649861 is about 352.0958895312.

The spelling of 43649861 in words is "forty-three million, six hundred forty-nine thousand, eight hundred sixty-one".