12661623436 has 36 divisors (see below), whose sum is σ = 27834650704. Its totient is φ = 4933098720.

The previous prime is 12661623419. The next prime is 12661623439. The reversal of 12661623436 is 63432616621.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (12661623439) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1865211 + ... + 1871986.

Almost surely, 2^12661623436 is an apocalyptic number.

It is an amenable number.

12661623436 is an abundant number, since it is smaller than the sum of its proper divisors (15173027268).

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

12661623436 is a wasteful number, since it uses less digits than its factorization.

12661623436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3737230 (or 3737217 counting only the distinct ones).

The product of its digits is 186624, while the sum is 40.

The spelling of 12661623436 in words is "twelve billion, six hundred sixty-one million, six hundred twenty-three thousand, four hundred thirty-six".