211221000122020 has 96 divisors (see below), whose sum is σ = 536851083944448. Its totient is φ = 68145852352512.

The previous prime is 211221000122017. The next prime is 211221000122029. The reversal of 211221000122020 is 20221000122112.

It is a happy number.

It is a super-2 number, since 2×211221000122020² (a number of 29 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 211221000121985 and 211221000122003.

It is not an unprimeable number, because it can be changed into a prime (211221000122029) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4253394 + ... + 20988886.

It is an arithmetic number, because the mean of its divisors is an integer number (5592198791088).

Almost surely, 2^{211221000122020} is an apocalyptic number.

211221000122020 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 211221000122020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (268425541972224).

211221000122020 is an abundant number, since it is smaller than the sum of its proper divisors (325630083822428).

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

211221000122020 is a wasteful number, since it uses less digits than its factorization.

211221000122020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16740829 (or 16740827 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 211221000122020 its reverse (20221000122112), we get a palindrome (231442000244132).

The spelling of 211221000122020 in words is "two hundred eleven trillion, two hundred twenty-one billion, one hundred twenty-two thousand, twenty".