212221122021 has 24 divisors (see below), whose sum is σ = 328220394840. Its totient is φ = 131662181376.

The previous prime is 212221121993. The next prime is 212221122031. The reversal of 212221122021 is 120221122212.

It is a happy number.

212221122021 is a `hidden beast` number, since 212 + 2 + 211 + 220 + 21 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 265853025 + 211955268996 = 16305^2 + 460386^2 .

It is not a de Polignac number, because 212221122021 - 2¹¹ = 212221119973 is a prime.

It is a super-2 number, since 2×212221122021² (a number of 23 digits) contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 212221121985 and 212221122003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212221122031) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7778890 + ... + 7806123.

It is an arithmetic number, because the mean of its divisors is an integer number (13675849785).

Almost surely, 2^212221122021 is an apocalyptic number.

It is an amenable number.

212221122021 is a deficient number, since it is larger than the sum of its proper divisors (115999272819).

212221122021 is a wasteful number, since it uses less digits than its factorization.

212221122021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15585125 (or 15585122 counting only the distinct ones).

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

Adding to 212221122021 its reverse (120221122212), we get a palindrome (332442244233).

The spelling of 212221122021 in words is "two hundred twelve billion, two hundred twenty-one million, one hundred twenty-two thousand, twenty-one".