68840681978 has 16 divisors (see below), whose sum is σ = 104126475264. Its totient is φ = 34132129920.

The previous prime is 68840681971. The next prime is 68840682007. The reversal of 68840681978 is 87918604886.

It is a super-2 number, since 2×68840681978² (a number of 22 digits) contains 22 as substring.

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 7 ways as a sum of consecutive naturals, for example, 445133 + ... + 579503.

It is an arithmetic number, because the mean of its divisors is an integer number (6507904704).

Almost surely, 2^68840681978 is an apocalyptic number.

68840681978 is a deficient number, since it is larger than the sum of its proper divisors (35285793286).

68840681978 is a wasteful number, since it uses less digits than its factorization.

68840681978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136517.

The product of its (nonzero) digits is 37158912, while the sum is 65.

The spelling of 68840681978 in words is "sixty-eight billion, eight hundred forty million, six hundred eighty-one thousand, nine hundred seventy-eight".