67640813388 has 18 divisors (see below), whose sum is σ = 170980945044. Its totient is φ = 22546937784.

The previous prime is 67640813363. The next prime is 67640813479. The reversal of 67640813388 is 88331804676.

It is a tau number, because it is divible by the number of its divisors (18).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 939455706 + ... + 939455777.

Almost surely, 2^67640813388 is an apocalyptic number.

It is an amenable number.

67640813388 is an abundant number, since it is smaller than the sum of its proper divisors (103340131656).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

67640813388 is a wasteful number, since it uses less digits than its factorization.

67640813388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1878911493 (or 1878911488 counting only the distinct ones).

The product of its (nonzero) digits is 4644864, while the sum is 54.

The spelling of 67640813388 in words is "sixty-seven billion, six hundred forty million, eight hundred thirteen thousand, three hundred eighty-eight".