12689684388 has 18 divisors (see below), whose sum is σ = 32076702294. Its totient is φ = 4229894784.

The previous prime is 12689684387. The next prime is 12689684419. The reversal of 12689684388 is 88348698621.

It can be written as a sum of positive squares in only one way, i.e., 12552513444 + 137170944 = 112038^2 + 11712^2 .

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

It is a super-2 number, since 2×12689684388² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (12689684387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 176245581 + ... + 176245652.

Almost surely, 2^12689684388 is an apocalyptic number.

12689684388 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

12689684388 is an abundant number, since it is smaller than the sum of its proper divisors (19387017906).

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

12689684388 is a wasteful number, since it uses less digits than its factorization.

12689684388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 352491243 (or 352491238 counting only the distinct ones).

The product of its digits is 31850496, while the sum is 63.

The spelling of 12689684388 in words is "twelve billion, six hundred eighty-nine million, six hundred eighty-four thousand, three hundred eighty-eight".