61665606943 has 2 divisors, whose sum is σ = 61665606944. Its totient is φ = 61665606942.

The previous prime is 61665606923. The next prime is 61665606949. The reversal of 61665606943 is 34960656616.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61665606943 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61665606949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30832803471 + 30832803472.

It is an arithmetic number, because the mean of its divisors is an integer number (30832803472).

Almost surely, 2^61665606943 is an apocalyptic number.

61665606943 is a deficient number, since it is larger than the sum of its proper divisors (1).

61665606943 is an equidigital number, since it uses as much as digits as its factorization.

61665606943 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4199040, while the sum is 52.

The spelling of 61665606943 in words is "sixty-one billion, six hundred sixty-five million, six hundred six thousand, nine hundred forty-three".