12991572 has 72 divisors (see below), whose sum is σ = 36560160. Its totient is φ = 3856320.

The previous prime is 12991571. The next prime is 12991603. The reversal of 12991572 is 27519921.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12991571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20679 + ... + 21297.

It is an arithmetic number, because the mean of its divisors is an integer number (507780).

Almost surely, 2^12991572 is an apocalyptic number.

12991572 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12991572, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18280080).

12991572 is an abundant number, since it is smaller than the sum of its proper divisors (23568588).

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

12991572 is a wasteful number, since it uses less digits than its factorization.

12991572 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 693 (or 688 counting only the distinct ones).

The product of its digits is 11340, while the sum is 36.

The square root of 12991572 is about 3604.3823326612. The cubic root of 12991572 is about 235.0826448418.

The spelling of 12991572 in words is "twelve million, nine hundred ninety-one thousand, five hundred seventy-two".