12081636 has 90 divisors (see below), whose sum is σ = 36788598. Its totient is φ = 3447360.

The previous prime is 12081631. The next prime is 12081653. The reversal of 12081636 is 63618021.

12081636 is a `hidden beast` number, since 1 + 20 + 8 + 1 + 636 = 666.

12081636 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 6350400 + 5731236 = 2520^2 + 2394^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12081631) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 15496 + ... + 16256.

Almost surely, 2^12081636 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12081636, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18394299).

12081636 is an abundant number, since it is smaller than the sum of its proper divisors (24706962).

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

12081636 is a wasteful number, since it uses less digits than its factorization.

12081636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 791 (or 773 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 12081636 is about 3475.8647844817. The cubic root of 12081636 is about 229.4608417107.

Adding to 12081636 its reverse (63618021), we get a palindrome (75699657).

The spelling of 12081636 in words is "twelve million, eighty-one thousand, six hundred thirty-six".