12891000 has 64 divisors (see below), whose sum is σ = 40229280. Its totient is φ = 3436800.

The previous prime is 12890989. The next prime is 12891007. The reversal of 12891000 is 19821.

Added to its reverse (19821) it gives a triangular number (12910821 = T₅₀₈₁).

12891000 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12891007) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 852 + ... + 5148.

Almost surely, 2^12891000 is an apocalyptic number.

12891000 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 12891000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20114640).

12891000 is an abundant number, since it is smaller than the sum of its proper divisors (27338280).

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

12891000 is a wasteful number, since it uses less digits than its factorization.

12891000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4321 (or 4307 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 21.

The square root of 12891000 is about 3590.4038770033. The cubic root of 12891000 is about 234.4744555685.

Adding to 12891000 its reverse (19821), we get a triangular number (12910821 = T₅₀₈₁).

The spelling of 12891000 in words is "twelve million, eight hundred ninety-one thousand".