6661993759 has 2 divisors, whose sum is σ = 6661993760. Its totient is φ = 6661993758.

The previous prime is 6661993747. The next prime is 6661993801. The reversal of 6661993759 is 9573991666.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6661993759 - 2²³ = 6653605151 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 6661993697 and 6661993706.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6661993159) 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, 3330996879 + 3330996880.

It is an arithmetic number, because the mean of its divisors is an integer number (3330996880).

Almost surely, 2^6661993759 is an apocalyptic number.

6661993759 is a deficient number, since it is larger than the sum of its proper divisors (1).

6661993759 is an equidigital number, since it uses as much as digits as its factorization.

6661993759 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16533720, while the sum is 61.

The square root of 6661993759 is about 81621.0374780914. The cubic root of 6661993759 is about 1881.6322175320.

The spelling of 6661993759 in words is "six billion, six hundred sixty-one million, nine hundred ninety-three thousand, seven hundred fifty-nine".