21213405331266 has 8 divisors (see below), whose sum is σ = 42426810662544. Its totient is φ = 7071135110420.

The previous prime is 21213405331231. The next prime is 21213405331333. The reversal of 21213405331266 is 66213350431212.

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

21213405331266 is an admirable number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1767783777600 + ... + 1767783777611.

It is an arithmetic number, because the mean of its divisors is an integer number (5303351332818).

Almost surely, 2^{21213405331266} is an apocalyptic number.

21213405331266 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21213405331266 is a wasteful number, since it uses less digits than its factorization.

21213405331266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3535567555216.

The product of its (nonzero) digits is 155520, while the sum is 39.

Adding to 21213405331266 its reverse (66213350431212), we get a palindrome (87426755762478).

The spelling of 21213405331266 in words is "twenty-one trillion, two hundred thirteen billion, four hundred five million, three hundred thirty-one thousand, two hundred sixty-six".