66688888997 has 2 divisors, whose sum is σ = 66688888998. Its totient is φ = 66688888996.

The previous prime is 66688888949. The next prime is 66688889021. The reversal of 66688888997 is 79988888666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51459107716 + 15229781281 = 226846^2 + 123409^2 .

It is a cyclic number.

It is not a de Polignac number, because 66688888997 - 2¹² = 66688884901 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66688888397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33344444498 + 33344444499.

It is an arithmetic number, because the mean of its divisors is an integer number (33344444499).

Almost surely, 2^66688888997 is an apocalyptic number.

It is an amenable number.

66688888997 is a deficient number, since it is larger than the sum of its proper divisors (1).

66688888997 is an equidigital number, since it uses as much as digits as its factorization.

66688888997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4013162496, while the sum is 83.

The spelling of 66688888997 in words is "sixty-six billion, six hundred eighty-eight million, eight hundred eighty-eight thousand, nine hundred ninety-seven".