20111221201020 has 48 divisors (see below), whose sum is σ = 56330072211840. Its totient is φ = 5361215858496.

The previous prime is 20111221200997. The next prime is 20111221201033. The reversal of 20111221201020 is 2010212211102.

It is a super-2 number, since 2×20111221201020² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 55331782 + ... + 55694061.

It is an arithmetic number, because the mean of its divisors is an integer number (1173543171080).

Almost surely, 2^{20111221201020} is an apocalyptic number.

20111221201020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20111221201020 is an abundant number, since it is smaller than the sum of its proper divisors (36218851010820).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20111221201020 is a wasteful number, since it uses less digits than its factorization.

20111221201020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111028874 (or 111028872 counting only the distinct ones).

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

Adding to 20111221201020 its reverse (2010212211102), we get a palindrome (22121433412122).

The spelling of 20111221201020 in words is "twenty trillion, one hundred eleven billion, two hundred twenty-one million, two hundred one thousand, twenty".