12005347821 has 8 divisors (see below), whose sum is σ = 16070904864. Its totient is φ = 7971678000.

The previous prime is 12005347811. The next prime is 12005347831. The reversal of 12005347821 is 12874350021.

It is an interprime number because it is at equal distance from previous prime (12005347811) and next prime (12005347831).

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

It is not a de Polignac number, because 12005347821 - 2¹¹ = 12005345773 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12005347811) 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, 7970926 + ... + 7972431.

It is an arithmetic number, because the mean of its divisors is an integer number (2008863108).

Almost surely, 2^12005347821 is an apocalyptic number.

It is an amenable number.

12005347821 is a deficient number, since it is larger than the sum of its proper divisors (4065557043).

12005347821 is a wasteful number, since it uses less digits than its factorization.

12005347821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15943611.

The product of its (nonzero) digits is 13440, while the sum is 33.

Adding to 12005347821 its reverse (12874350021), we get a palindrome (24879697842).

The spelling of 12005347821 in words is "twelve billion, five million, three hundred forty-seven thousand, eight hundred twenty-one".