20001212101221 has 64 divisors (see below), whose sum is σ = 29801908819200. Its totient is φ = 11852076681216.

The previous prime is 20001212101201. The next prime is 20001212101267. The reversal of 20001212101221 is 12210121210002.

It is not a de Polignac number, because 20001212101221 - 2¹⁹ = 20001211576933 is a prime.

It is a super-4 number, since 4×20001212101221⁴ (a number of 54 digits) contains 4444 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20001212101221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20001212101201) 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 63 ways as a sum of consecutive naturals, for example, 63425625 + ... + 63740193.

It is an arithmetic number, because the mean of its divisors is an integer number (465654825300).

Almost surely, 2^{20001212101221} is an apocalyptic number.

It is an amenable number.

20001212101221 is a deficient number, since it is larger than the sum of its proper divisors (9800696717979).

20001212101221 is a wasteful number, since it uses less digits than its factorization.

20001212101221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 315078.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 20001212101221 its reverse (12210121210002), we get a palindrome (32211333311223).

The spelling of 20001212101221 in words is "twenty trillion, one billion, two hundred twelve million, one hundred one thousand, two hundred twenty-one".