20100221011220 has 96 divisors (see below), whose sum is σ = 48789512545536. Its totient is φ = 6813278208000.

The previous prime is 20100221011207. The next prime is 20100221011243. The reversal of 20100221011220 is 2211012200102.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a junction number, because it is equal to n+sod(n) for n = 20100221011195 and 20100221011204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8616980 + ... + 10698260.

It is an arithmetic number, because the mean of its divisors is an integer number (508224089016).

Almost surely, 2^{20100221011220} is an apocalyptic number.

20100221011220 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 20100221011220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24394756272768).

20100221011220 is an abundant number, since it is smaller than the sum of its proper divisors (28689291534316).

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

20100221011220 is a wasteful number, since it uses less digits than its factorization.

20100221011220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2082081 (or 2082079 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 20100221011220 its reverse (2211012200102), we get a palindrome (22311233211322).

The spelling of 20100221011220 in words is "twenty trillion, one hundred billion, two hundred twenty-one million, eleven thousand, two hundred twenty".