12991860 has 144 divisors (see below), whose sum is σ = 47113920. Its totient is φ = 2963520.

The previous prime is 12991813. The next prime is 12991871. The reversal of 12991860 is 6819921.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 26215 + ... + 26705.

It is an arithmetic number, because the mean of its divisors is an integer number (327180).

Almost surely, 2^12991860 is an apocalyptic number.

12991860 is a gapful number since it is divisible by the number (10) 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 12991860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23556960).

12991860 is an abundant number, since it is smaller than the sum of its proper divisors (34122060).

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

12991860 is a wasteful number, since it uses less digits than its factorization.

12991860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 523 (or 508 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 36.

The square root of 12991860 is about 3604.4222838064. The cubic root of 12991860 is about 235.0843819501.

The spelling of 12991860 in words is "twelve million, nine hundred ninety-one thousand, eight hundred sixty".