221211212020 has 24 divisors (see below), whose sum is σ = 469142990568. Its totient is φ = 87608400000.

The previous prime is 221211212017. The next prime is 221211212021. The reversal of 221211212020 is 20212112122.

It is a happy number.

221211212020 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 130474108944 + 90737103076 = 361212^2 + 301226^2 .

It is a super-5 number, since 5×221211212020⁵ (a number of 58 digits) contains 55555 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 221211211985 and 221211212003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221211212021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 54753231 + ... + 54757270.

It is an arithmetic number, because the mean of its divisors is an integer number (19547624607).

Almost surely, 2^221211212020 is an apocalyptic number.

221211212020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221211212020 is an abundant number, since it is smaller than the sum of its proper divisors (247931778548).

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

221211212020 is a wasteful number, since it uses less digits than its factorization.

221211212020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109510611 (or 109510609 counting only the distinct ones).

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

Adding to 221211212020 its reverse (20212112122), we get a palindrome (241423324142).

The spelling of 221211212020 in words is "two hundred twenty-one billion, two hundred eleven million, two hundred twelve thousand, twenty".