12091861 has 2 divisors, whose sum is σ = 12091862. Its totient is φ = 12091860.

The previous prime is 12091789. The next prime is 12091867. The reversal of 12091861 is 16819021.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11628100 + 463761 = 3410^2 + 681^2 .

It is a cyclic number.

It is not a de Polignac number, because 12091861 - 2¹¹ = 12089813 is a prime.

It is a super-3 number, since 3×12091861³ (a number of 22 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12091867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6045930 + 6045931.

It is an arithmetic number, because the mean of its divisors is an integer number (6045931).

Almost surely, 2^12091861 is an apocalyptic number.

It is an amenable number.

12091861 is a deficient number, since it is larger than the sum of its proper divisors (1).

12091861 is an equidigital number, since it uses as much as digits as its factorization.

12091861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 28.

The square root of 12091861 is about 3477.3353303931. The cubic root of 12091861 is about 229.5255563328.

The spelling of 12091861 in words is "twelve million, ninety-one thousand, eight hundred sixty-one".