68220779939 has 4 divisors (see below), whose sum is σ = 73468532256. Its totient is φ = 62973027624.

The previous prime is 68220779929. The next prime is 68220779947. The reversal of 68220779939 is 93997702286.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93997702286 = 2 ⋅46998851143.

It is not a de Polignac number, because 68220779939 - 2²⁴ = 68204002723 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68220779909) 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, 2623876139 + ... + 2623876164.

It is an arithmetic number, because the mean of its divisors is an integer number (18367133064).

Almost surely, 2^68220779939 is an apocalyptic number.

68220779939 is a deficient number, since it is larger than the sum of its proper divisors (5247752317).

68220779939 is a wasteful number, since it uses less digits than its factorization.

68220779939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5247752316.

The product of its (nonzero) digits is 20575296, while the sum is 62.

The spelling of 68220779939 in words is "sixty-eight billion, two hundred twenty million, seven hundred seventy-nine thousand, nine hundred thirty-nine".