20111220012221 has 24 divisors (see below), whose sum is σ = 22573699077384. Its totient is φ = 17809890658560.

The previous prime is 20111220012217. The next prime is 20111220012271. The reversal of 20111220012221 is 12221002211102.

It can be written as a sum of positive squares in 12 ways, for example, as 14885360004025 + 5225860008196 = 3858155^2 + 2286014^2 .

It is not a de Polignac number, because 20111220012221 - 2² = 20111220012217 is a prime.

It is a super-2 number, since 2×20111220012221² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20111220012221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20111220012271) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 4141790 + ... + 7574751.

It is an arithmetic number, because the mean of its divisors is an integer number (940570794891).

Almost surely, 2^{20111220012221} is an apocalyptic number.

It is an amenable number.

20111220012221 is a deficient number, since it is larger than the sum of its proper divisors (2462479065163).

20111220012221 is a wasteful number, since it uses less digits than its factorization.

20111220012221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11716769 (or 11716740 counting only the distinct ones).

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

Adding to 20111220012221 its reverse (12221002211102), we get a palindrome (32332222223323).

The spelling of 20111220012221 in words is "twenty trillion, one hundred eleven billion, two hundred twenty million, twelve thousand, two hundred twenty-one".