43666575908861 has 2 divisors, whose sum is σ = 43666575908862. Its totient is φ = 43666575908860.

The previous prime is 43666575908807. The next prime is 43666575908869. The reversal of 43666575908861 is 16880957566634.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 43666575908761 + 100 = 6608069^2 + 10^2 .

It is a cyclic number.

It is not a de Polignac number, because 43666575908861 - 2¹⁰ = 43666575907837 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43666575908869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21833287954430 + 21833287954431.

It is an arithmetic number, because the mean of its divisors is an integer number (21833287954431).

Almost surely, 2^{43666575908861} is an apocalyptic number.

It is an amenable number.

43666575908861 is a deficient number, since it is larger than the sum of its proper divisors (1).

43666575908861 is an equidigital number, since it uses as much as digits as its factorization.

43666575908861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1567641600, while the sum is 74.

The spelling of 43666575908861 in words is "forty-three trillion, six hundred sixty-six billion, five hundred seventy-five million, nine hundred eight thousand, eight hundred sixty-one".