66105001691 has 2 divisors, whose sum is σ = 66105001692. Its totient is φ = 66105001690.

The previous prime is 66105001673. The next prime is 66105001709. The reversal of 66105001691 is 19610050166.

It is a balanced prime because it is at equal distance from previous prime (66105001673) and next prime (66105001709).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66105001691 is a prime.

It is a super-2 number, since 2×66105001691² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66105001091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33052500845 + 33052500846.

It is an arithmetic number, because the mean of its divisors is an integer number (33052500846).

Almost surely, 2^66105001691 is an apocalyptic number.

66105001691 is a deficient number, since it is larger than the sum of its proper divisors (1).

66105001691 is an equidigital number, since it uses as much as digits as its factorization.

66105001691 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9720, while the sum is 35.

The spelling of 66105001691 in words is "sixty-six billion, one hundred five million, one thousand, six hundred ninety-one".