12891997 has 4 divisors (see below), whose sum is σ = 12941280. Its totient is φ = 12842716.

The previous prime is 12891973. The next prime is 12892027. The reversal of 12891997 is 79919821.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 12891997 - 2⁷ = 12891869 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12891497) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24247 + ... + 24772.

It is an arithmetic number, because the mean of its divisors is an integer number (3235320).

Almost surely, 2^12891997 is an apocalyptic number.

It is an amenable number.

12891997 is a deficient number, since it is larger than the sum of its proper divisors (49283).

12891997 is an equidigital number, since it uses as much as digits as its factorization.

12891997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49282.

The product of its digits is 81648, while the sum is 46.

The square root of 12891997 is about 3590.5427166377. The cubic root of 12891997 is about 234.4805002251.

The spelling of 12891997 in words is "twelve million, eight hundred ninety-one thousand, nine hundred ninety-seven".