21211010100120 has 256 divisors, whose sum is σ = 67348948746240. Its totient is φ = 5333540179968.

The previous prime is 21211010100113. The next prime is 21211010100121. The reversal of 21211010100120 is 2100101011212.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 21211010100096 and 21211010100105.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211010100121) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 54838924 + ... + 55224356.

It is an arithmetic number, because the mean of its divisors is an integer number (263081831040).

Almost surely, 2^{21211010100120} is an apocalyptic number.

21211010100120 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 21211010100120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33674474373120).

21211010100120 is an abundant number, since it is smaller than the sum of its proper divisors (46137938646120).

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

21211010100120 is a wasteful number, since it uses less digits than its factorization.

21211010100120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 385754 (or 385750 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21211010100120 its reverse (2100101011212), we get a palindrome (23311111111332).

The spelling of 21211010100120 in words is "twenty-one trillion, two hundred eleven billion, ten million, one hundred thousand, one hundred twenty".