12891387 has 8 divisors (see below), whose sum is σ = 17224704. Its totient is φ = 8576168.

The previous prime is 12891353. The next prime is 12891409. The reversal of 12891387 is 78319821.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 12891387 - 2⁷ = 12891259 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12891187) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2763 + ... + 5780.

It is an arithmetic number, because the mean of its divisors is an integer number (2153088).

Almost surely, 2^12891387 is an apocalyptic number.

12891387 is a deficient number, since it is larger than the sum of its proper divisors (4333317).

12891387 is an equidigital number, since it uses as much as digits as its factorization.

12891387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9049.

The product of its digits is 24192, while the sum is 39.

The square root of 12891387 is about 3590.4577702572. The cubic root of 12891387 is about 234.4768019265.

The spelling of 12891387 in words is "twelve million, eight hundred ninety-one thousand, three hundred eighty-seven".