12181310021 has 8 divisors (see below), whose sum is σ = 12228486144. Its totient is φ = 12134214720.

The previous prime is 12181309991. The next prime is 12181310047. The reversal of 12181310021 is 12001318121.

It is a happy number.

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-12181310021 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 12181309975 and 12181310002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12181310821) 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, 291005 + ... + 330221.

It is an arithmetic number, because the mean of its divisors is an integer number (1528560768).

Almost surely, 2^12181310021 is an apocalyptic number.

It is an amenable number.

12181310021 is a deficient number, since it is larger than the sum of its proper divisors (47176123).

12181310021 is an equidigital number, since it uses as much as digits as its factorization.

12181310021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40411.

The product of its (nonzero) digits is 96, while the sum is 20.

Adding to 12181310021 its reverse (12001318121), we get a palindrome (24182628142).

The spelling of 12181310021 in words is "twelve billion, one hundred eighty-one million, three hundred ten thousand, twenty-one".