12891619 has 4 divisors (see below), whose sum is σ = 13883296. Its totient is φ = 11899944.

The previous prime is 12891607. The next prime is 12891623. The reversal of 12891619 is 91619821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 91619821 = 2243 ⋅40847.

It is a cyclic number.

It is not a de Polignac number, because 12891619 - 2⁵ = 12891587 is a prime.

It is a super-2 number, since 2×12891619² = 332387680882322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12891649) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 495819 + ... + 495844.

It is an arithmetic number, because the mean of its divisors is an integer number (3470824).

Almost surely, 2^12891619 is an apocalyptic number.

12891619 is a deficient number, since it is larger than the sum of its proper divisors (991677).

12891619 is an equidigital number, since it uses as much as digits as its factorization.

12891619 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 991676.

The product of its digits is 7776, while the sum is 37.

The square root of 12891619 is about 3590.4900779699. The cubic root of 12891619 is about 234.4782085063.

The spelling of 12891619 in words is "twelve million, eight hundred ninety-one thousand, six hundred nineteen".