12991400 has 48 divisors (see below), whose sum is σ = 31990140. Its totient is φ = 4889600.

The previous prime is 12991397. The next prime is 12991423. The reversal of 12991400 is 419921.

12991400 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 6 ways, for example, as 9449476 + 3541924 = 3074^2 + 1882^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 12991400.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1490 + ... + 5310.

Almost surely, 2^12991400 is an apocalyptic number.

12991400 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 12991400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15995070).

12991400 is an abundant number, since it is smaller than the sum of its proper divisors (18998740).

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

12991400 is a wasteful number, since it uses less digits than its factorization.

12991400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3854 (or 3845 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 26.

The square root of 12991400 is about 3604.3584727382. The cubic root of 12991400 is about 235.0816073899.

The spelling of 12991400 in words is "twelve million, nine hundred ninety-one thousand, four hundred".