68692740649 has 9 divisors (see below), whose sum is σ = 74386953189. Its totient is φ = 63405538560.

The previous prime is 68692740643. The next prime is 68692740653. The reversal of 68692740649 is 94604729686.

The square root of 68692740649 is 262093.

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 3735043225 + 64957697424 = 61115^2 + 254868^2 .

It is not a de Polignac number, because 68692740649 - 2⁵ = 68692740617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68692740643) 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 in 8 ways as a sum of consecutive naturals, for example, 3397129 + ... + 3417289.

It is an arithmetic number, because the mean of its divisors is an integer number (8265217021).

Almost surely, 2^68692740649 is an apocalyptic number.

68692740649 is the 262093-rd square number.

68692740649 is the 131047-th centered octagonal number.

It is an amenable number.

68692740649 is a deficient number, since it is larger than the sum of its proper divisors (5694212540).

68692740649 is an frugal number, since it uses more digits than its factorization.

68692740649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40348 (or 20174 counting only the distinct ones).

The product of its (nonzero) digits is 31352832, while the sum is 61.

The spelling of 68692740649 in words is "sixty-eight billion, six hundred ninety-two million, seven hundred forty thousand, six hundred forty-nine".