66335608249 has 9 divisors (see below), whose sum is σ = 68186713581. Its totient is φ = 64533481920.

The previous prime is 66335608247. The next prime is 66335608267. The reversal of 66335608249 is 94280653366.

The square root of 66335608249 is 257557.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 31242330025 + 35093278224 = 176755^2 + 187332^2 .

It is not a de Polignac number, because 66335608249 - 2¹ = 66335608247 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66335608196 and 66335608205.

It is not an unprimeable number, because it can be changed into a prime (66335608247) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 9526129 + ... + 9533089.

It is an arithmetic number, because the mean of its divisors is an integer number (7576301509).

Almost surely, 2^66335608249 is an apocalyptic number.

66335608249 is the 257557-th square number.

66335608249 is the 128779-th centered octagonal number.

It is an amenable number.

66335608249 is a deficient number, since it is larger than the sum of its proper divisors (1851105332).

66335608249 is an frugal number, since it uses more digits than its factorization.

66335608249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13996 (or 6998 counting only the distinct ones).

The product of its (nonzero) digits is 5598720, while the sum is 52.

The spelling of 66335608249 in words is "sixty-six billion, three hundred thirty-five million, six hundred eight thousand, two hundred forty-nine".