12129581 has 8 divisors (see below), whose sum is σ = 12931200. Its totient is φ = 11344320.

The previous prime is 12129571. The next prime is 12129583. The reversal of 12129581 is 18592121.

12129581 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12129581 is a prime.

It is a super-2 number, since 2×12129581² = 294253470471122, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12129583) 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, 2540 + ... + 5541.

It is an arithmetic number, because the mean of its divisors is an integer number (1616400).

Almost surely, 2^12129581 is an apocalyptic number.

It is an amenable number.

12129581 is a deficient number, since it is larger than the sum of its proper divisors (801619).

12129581 is an equidigital number, since it uses as much as digits as its factorization.

12129581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8179.

The product of its digits is 1440, while the sum is 29.

The square root of 12129581 is about 3482.7548004417. The cubic root of 12129581 is about 229.7639733726.

The spelling of 12129581 in words is "twelve million, one hundred twenty-nine thousand, five hundred eighty-one".