21213205640612 has 12 divisors (see below), whose sum is σ = 37151085095040. Its totient is φ = 10598609899176.

The previous prime is 21213205640593. The next prime is 21213205640647. The reversal of 21213205640612 is 21604650231212.

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, 1998224312 + ... + 1998234927.

It is an arithmetic number, because the mean of its divisors is an integer number (3095923757920).

Almost surely, 2^{21213205640612} is an apocalyptic number.

It is an amenable number.

21213205640612 is a deficient number, since it is larger than the sum of its proper divisors (15937879454428).

21213205640612 is a wasteful number, since it uses less digits than its factorization.

21213205640612 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3996460570 (or 3996460568 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 35.

Adding to 21213205640612 its reverse (21604650231212), we get a palindrome (42817855871824).

The spelling of 21213205640612 in words is "twenty-one trillion, two hundred thirteen billion, two hundred five million, six hundred forty thousand, six hundred twelve".