68688661609 has 8 divisors (see below), whose sum is σ = 68919188040. Its totient is φ = 68458206336.

The previous prime is 68688661607. The next prime is 68688661633. The reversal of 68688661609 is 90616688686.

It can be written as a sum of positive squares in 4 ways, for example, as 6087120400 + 62601541209 = 78020^2 + 250203^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 68688661609 - 2¹ = 68688661607 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68688661603) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2511999 + ... + 2539195.

It is an arithmetic number, because the mean of its divisors is an integer number (8614898505).

Almost surely, 2^68688661609 is an apocalyptic number.

It is an amenable number.

68688661609 is a deficient number, since it is larger than the sum of its proper divisors (230526431).

68688661609 is a wasteful number, since it uses less digits than its factorization.

68688661609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35579.

The product of its (nonzero) digits is 35831808, while the sum is 64.

The spelling of 68688661609 in words is "sixty-eight billion, six hundred eighty-eight million, six hundred sixty-one thousand, six hundred nine".