43665620161 has 2 divisors, whose sum is σ = 43665620162. Its totient is φ = 43665620160.

The previous prime is 43665620107. The next prime is 43665620197. The reversal of 43665620161 is 16102656634.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 43662609936 + 3010225 = 208956^2 + 1735^2 .

It is a cyclic number.

It is not a de Polignac number, because 43665620161 - 2¹⁵ = 43665587393 is a prime.

It is not a weakly prime, because it can be changed into another prime (43665620561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21832810080 + 21832810081.

It is an arithmetic number, because the mean of its divisors is an integer number (21832810081).

Almost surely, 2^43665620161 is an apocalyptic number.

It is an amenable number.

43665620161 is a deficient number, since it is larger than the sum of its proper divisors (1).

43665620161 is an equidigital number, since it uses as much as digits as its factorization.

43665620161 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 155520, while the sum is 40.

The spelling of 43665620161 in words is "forty-three billion, six hundred sixty-five million, six hundred twenty thousand, one hundred sixty-one".