68140813 has 4 divisors (see below), whose sum is σ = 73382428. Its totient is φ = 62899200.

The previous prime is 68140801. The next prime is 68140817. The reversal of 68140813 is 31804186.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 17489124 + 50651689 = 4182^2 + 7117^2 .

It is not a de Polignac number, because 68140813 - 2⁵ = 68140781 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68140817) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2620788 + ... + 2620813.

It is an arithmetic number, because the mean of its divisors is an integer number (18345607).

Almost surely, 2^68140813 is an apocalyptic number.

It is an amenable number.

68140813 is a deficient number, since it is larger than the sum of its proper divisors (5241615).

68140813 is a wasteful number, since it uses less digits than its factorization.

68140813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5241614.

The product of its (nonzero) digits is 4608, while the sum is 31.

The square root of 68140813 is about 8254.7448779475. The cubic root of 68140813 is about 408.4470561862.

Adding to 68140813 its reverse (31804186), we get a palindrome (99944999).

The spelling of 68140813 in words is "sixty-eight million, one hundred forty thousand, eight hundred thirteen".