61665606571 has 2 divisors, whose sum is σ = 61665606572. Its totient is φ = 61665606570.

The previous prime is 61665606533. The next prime is 61665606593. The reversal of 61665606571 is 17560656616.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 61665606571 - 2⁹ = 61665606059 is a prime.

It is not a weakly prime, because it can be changed into another prime (61665606671) 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, 30832803285 + 30832803286.

It is an arithmetic number, because the mean of its divisors is an integer number (30832803286).

Almost surely, 2^61665606571 is an apocalyptic number.

61665606571 is a deficient number, since it is larger than the sum of its proper divisors (1).

61665606571 is an equidigital number, since it uses as much as digits as its factorization.

61665606571 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1360800, while the sum is 49.

The spelling of 61665606571 in words is "sixty-one billion, six hundred sixty-five million, six hundred six thousand, five hundred seventy-one".