221212102201020 has 504 divisors, whose sum is σ = 857873385364464. Its totient is φ = 47588483238912.

The previous prime is 221212102201009. The next prime is 221212102201031. The reversal of 221212102201020 is 20102201212122.

It is a happy number.

221212102201020 is a `hidden beast` number, since 2 + 212 + 1 + 210 + 220 + 1 + 0 + 20 = 666.

221212102201020 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (221212102201009) and next prime (221212102201031).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 221212102200984 and 221212102201002.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 167 ways as a sum of consecutive naturals, for example, 3038119 + ... + 21252161.

It is an arithmetic number, because the mean of its divisors is an integer number (1702129732866).

Almost surely, 2^{221212102201020} is an apocalyptic number.

221212102201020 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 221212102201020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (428936692682232).

221212102201020 is an abundant number, since it is smaller than the sum of its proper divisors (636661283163444).

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

221212102201020 is a wasteful number, since it uses less digits than its factorization.

221212102201020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18214101 (or 18214077 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 221212102201020 its reverse (20102201212122), we get a palindrome (241314303413142).

The spelling of 221212102201020 in words is "two hundred twenty-one trillion, two hundred twelve billion, one hundred two million, two hundred one thousand, twenty".