43135661 has 2 divisors, whose sum is σ = 43135662. Its totient is φ = 43135660.

The previous prime is 43135637. The next prime is 43135691. The reversal of 43135661 is 16653134.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 41203561 + 1932100 = 6419^2 + 1390^2 .

It is a cyclic number.

It is not a de Polignac number, because 43135661 - 2⁶ = 43135597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43135621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21567830 + 21567831.

It is an arithmetic number, because the mean of its divisors is an integer number (21567831).

Almost surely, 2^43135661 is an apocalyptic number.

It is an amenable number.

43135661 is a deficient number, since it is larger than the sum of its proper divisors (1).

43135661 is an equidigital number, since it uses as much as digits as its factorization.

43135661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6480, while the sum is 29.

The square root of 43135661 is about 6567.7744327892. The cubic root of 43135661 is about 350.7078490952.

Adding to 43135661 its reverse (16653134), we get a palindrome (59788795).

The spelling of 43135661 in words is "forty-three million, one hundred thirty-five thousand, six hundred sixty-one".