43878661 has 2 divisors, whose sum is σ = 43878662. Its totient is φ = 43878660.

The previous prime is 43878643. The next prime is 43878673. The reversal of 43878661 is 16687834.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39614436 + 4264225 = 6294^2 + 2065^2 .

It is a cyclic number.

It is not a de Polignac number, because 43878661 - 2¹⁷ = 43747589 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43878631) 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, 21939330 + 21939331.

It is an arithmetic number, because the mean of its divisors is an integer number (21939331).

Almost surely, 2^43878661 is an apocalyptic number.

It is an amenable number.

43878661 is a deficient number, since it is larger than the sum of its proper divisors (1).

43878661 is an equidigital number, since it uses as much as digits as its factorization.

43878661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 193536, while the sum is 43.

The square root of 43878661 is about 6624.0969950628. The cubic root of 43878661 is about 352.7100128412.

The spelling of 43878661 in words is "forty-three million, eight hundred seventy-eight thousand, six hundred sixty-one".