21221561306006 has 8 divisors (see below), whose sum is σ = 33216356826864. Its totient is φ = 10149442363720.

The previous prime is 21221561305957. The next prime is 21221561306027. The reversal of 21221561306006 is 60060316512212.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 230669144585 + ... + 230669144676.

It is an arithmetic number, because the mean of its divisors is an integer number (4152044603358).

Almost surely, 2^{21221561306006} is an apocalyptic number.

21221561306006 is a deficient number, since it is larger than the sum of its proper divisors (11994795520858).

21221561306006 is a wasteful number, since it uses less digits than its factorization.

21221561306006 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 461338289286.

The product of its (nonzero) digits is 25920, while the sum is 35.

Adding to 21221561306006 its reverse (60060316512212), we get a palindrome (81281877818218).

The spelling of 21221561306006 in words is "twenty-one trillion, two hundred twenty-one billion, five hundred sixty-one million, three hundred six thousand, six".