21021221122012 has 24 divisors (see below), whose sum is σ = 36946111312656. Its totient is φ = 10465224388608.

The previous prime is 21021221121983. The next prime is 21021221122021. The reversal of 21021221122012 is 21022112212012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1984158 + ... + 6780805.

It is an arithmetic number, because the mean of its divisors is an integer number (1539421304694).

Almost surely, 2^{21021221122012} is an apocalyptic number.

It is an amenable number.

21021221122012 is a deficient number, since it is larger than the sum of its proper divisors (15924890190644).

21021221122012 is a wasteful number, since it uses less digits than its factorization.

21021221122012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8767557 (or 8767555 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21021221122012 its reverse (21022112212012), we get a palindrome (42043333334024).

The spelling of 21021221122012 in words is "twenty-one trillion, twenty-one billion, two hundred twenty-one million, one hundred twenty-two thousand, twelve".