20111221002120 has 256 divisors, whose sum is σ = 61628302310400. Its totient is φ = 5248445030400.

The previous prime is 20111221002113. The next prime is 20111221002137. The reversal of 20111221002120 is 2120012211102.

It is a super-2 number, since 2×20111221002120² (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 self number, because there is not a number n which added to its sum of digits gives 20111221002120.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 7908461569 + ... + 7908464111.

It is an arithmetic number, because the mean of its divisors is an integer number (240735555900).

Almost surely, 2^{20111221002120} is an apocalyptic number.

20111221002120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20111221002120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30814151155200).

20111221002120 is an abundant number, since it is smaller than the sum of its proper divisors (41517081308280).

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

20111221002120 is a wasteful number, since it uses less digits than its factorization.

20111221002120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5280 (or 5276 counting only the distinct ones).

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

Adding to 20111221002120 its reverse (2120012211102), we get a palindrome (22231233213222).

The spelling of 20111221002120 in words is "twenty trillion, one hundred eleven billion, two hundred twenty-one million, two thousand, one hundred twenty".