12031681 has 4 divisors (see below), whose sum is σ = 12084912. Its totient is φ = 11978452.

The previous prime is 12031667. The next prime is 12031687. The reversal of 12031681 is 18613021.

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 12031681 - 2⁹ = 12031169 is a prime.

It is a super-2 number, since 2×12031681² = 289522695371522, which contains 22 as substring.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12031687) 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, 26275 + ... + 26728.

It is an arithmetic number, because the mean of its divisors is an integer number (3021228).

Almost surely, 2^12031681 is an apocalyptic number.

It is an amenable number.

12031681 is a deficient number, since it is larger than the sum of its proper divisors (53231).

12031681 is an equidigital number, since it uses as much as digits as its factorization.

12031681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53230.

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 12031681 is about 3468.6713594689. The cubic root of 12031681 is about 229.1441475319.

The spelling of 12031681 in words is "twelve million, thirty-one thousand, six hundred eighty-one".