12991999 has 8 divisors (see below), whose sum is σ = 13169520. Its totient is φ = 12816000.

The previous prime is 12991981. The next prime is 12992003. The reversal of 12991999 is 99919921.

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 12991999 - 2⁵ = 12991967 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 (12991939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32199 + ... + 32599.

It is an arithmetic number, because the mean of its divisors is an integer number (1646190).

Almost surely, 2^12991999 is an apocalyptic number.

12991999 is a deficient number, since it is larger than the sum of its proper divisors (177521).

12991999 is a wasteful number, since it uses less digits than its factorization.

12991999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 761.

The product of its digits is 118098, while the sum is 49.

The square root of 12991999 is about 3604.4415656243. The cubic root of 12991999 is about 235.0852203369.

The spelling of 12991999 in words is "twelve million, nine hundred ninety-one thousand, nine hundred ninety-nine".