20001211112220 has 192 divisors, whose sum is σ = 61596004538880. Its totient is φ = 4818948406272.

The previous prime is 20001211112213. The next prime is 20001211112231. The reversal of 20001211112220 is 2221111210002.

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 20001211112220.

It is a congruent number.

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, 16744107 + ... + 17898813.

It is an arithmetic number, because the mean of its divisors is an integer number (320812523640).

Almost surely, 2^{20001211112220} is an apocalyptic number.

20001211112220 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 20001211112220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30798002269440).

20001211112220 is an abundant number, since it is smaller than the sum of its proper divisors (41594793426660).

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

20001211112220 is a wasteful number, since it uses less digits than its factorization.

20001211112220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1155204 (or 1155202 counting only the distinct ones).

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

Adding to 20001211112220 its reverse (2221111210002), we get a palindrome (22222322322222).

The spelling of 20001211112220 in words is "twenty trillion, one billion, two hundred eleven million, one hundred twelve thousand, two hundred twenty".