68840681977 has 4 divisors (see below), whose sum is σ = 72890133876. Its totient is φ = 64791230080.

The previous prime is 68840681971. The next prime is 68840682007. The reversal of 68840681977 is 77918604886.

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 50310938601 + 18529743376 = 224301^2 + 136124^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-68840681977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68840681971) 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, 2024725924 + ... + 2024725957.

It is an arithmetic number, because the mean of its divisors is an integer number (18222533469).

Almost surely, 2^68840681977 is an apocalyptic number.

It is an amenable number.

68840681977 is a deficient number, since it is larger than the sum of its proper divisors (4049451899).

68840681977 is a wasteful number, since it uses less digits than its factorization.

68840681977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4049451898.

The product of its (nonzero) digits is 32514048, while the sum is 64.

The spelling of 68840681977 in words is "sixty-eight billion, eight hundred forty million, six hundred eighty-one thousand, nine hundred seventy-seven".