20121012012221 has 16 divisors (see below), whose sum is σ = 21081539945088. Its totient is φ = 19167640800000.

The previous prime is 20121012012217. The next prime is 20121012012271. The reversal of 20121012012221 is 12221021012102.

It is a cyclic number.

It is not a de Polignac number, because 20121012012221 - 2² = 20121012012217 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20121012012221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121012012271) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 61035185 + ... + 61363961.

It is an arithmetic number, because the mean of its divisors is an integer number (1317596246568).

Almost surely, 2^{20121012012221} is an apocalyptic number.

It is an amenable number.

20121012012221 is a deficient number, since it is larger than the sum of its proper divisors (960527932867).

20121012012221 is a wasteful number, since it uses less digits than its factorization.

20121012012221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 339652.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 20121012012221 its reverse (12221021012102), we get a palindrome (32342033024323).

The spelling of 20121012012221 in words is "twenty trillion, one hundred twenty-one billion, twelve million, twelve thousand, two hundred twenty-one".