12099991 has 2 divisors, whose sum is σ = 12099992. Its totient is φ = 12099990.

The previous prime is 12099959. The next prime is 12100003. The reversal of 12099991 is 19999021.

12099991 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 12099991 - 2⁵ = 12099959 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12099911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6049995 + 6049996.

It is an arithmetic number, because the mean of its divisors is an integer number (6049996).

Almost surely, 2^12099991 is an apocalyptic number.

12099991 is a deficient number, since it is larger than the sum of its proper divisors (1).

12099991 is an equidigital number, since it uses as much as digits as its factorization.

12099991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13122, while the sum is 40.

The square root of 12099991 is about 3478.5041325259. The cubic root of 12099991 is about 229.5769855466.

It can be divided in two parts, 1209999 and 1, that added together give a square (1210000 = 1100²).

The spelling of 12099991 in words is "twelve million, ninety-nine thousand, nine hundred ninety-one".