21218408008006 has 64 divisors (see below), whose sum is σ = 35360638905600. Its totient is φ = 9467545737600.

The previous prime is 21218408008003. The next prime is 21218408008069. The reversal of 21218408008006 is 60080080481212.

It is a self number, because there is not a number n which added to its sum of digits gives 21218408008006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21218408008001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5276896276 + ... + 5276900296.

It is an arithmetic number, because the mean of its divisors is an integer number (552509982900).

Almost surely, 2^{21218408008006} is an apocalyptic number.

21218408008006 is a deficient number, since it is larger than the sum of its proper divisors (14142230897594).

21218408008006 is a wasteful number, since it uses less digits than its factorization.

21218408008006 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8965.

The product of its (nonzero) digits is 49152, while the sum is 40.

Adding to 21218408008006 its reverse (60080080481212), we get a palindrome (81298488489218).

The spelling of 21218408008006 in words is "twenty-one trillion, two hundred eighteen billion, four hundred eight million, eight thousand, six".