12081981 has 8 divisors (see below), whose sum is σ = 16125760. Its totient is φ = 8046432.

The previous prime is 12081977. The next prime is 12081989. The reversal of 12081981 is 18918021.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 12081981 - 2² = 12081977 is a prime.

It is a super-2 number, since 2×12081981² = 291948529768722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12081989) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3576 + ... + 6078.

It is an arithmetic number, because the mean of its divisors is an integer number (2015720).

Almost surely, 2^12081981 is an apocalyptic number.

It is an amenable number.

12081981 is a deficient number, since it is larger than the sum of its proper divisors (4043779).

12081981 is a wasteful number, since it uses less digits than its factorization.

12081981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4115.

The product of its (nonzero) digits is 1152, while the sum is 30.

The square root of 12081981 is about 3475.9144120648. The cubic root of 12081981 is about 229.4630258309.

The spelling of 12081981 in words is "twelve million, eighty-one thousand, nine hundred eighty-one".