221201222012021 has 4 divisors (see below), whose sum is σ = 221726640592044. Its totient is φ = 220675803432000.

The previous prime is 221201222012009. The next prime is 221201222012063. The reversal of 221201222012021 is 120210222102122.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 687216130225 + 220514005881796 = 828985^2 + 14849714^2 .

It is a cyclic number.

It is not a de Polignac number, because 221201222012021 - 2¹⁰ = 221201222010997 is a prime.

It is a super-2 number, since 2×221201222012021² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221201222011984 and 221201222012002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221201228012021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 262709289380 + ... + 262709290221.

It is an arithmetic number, because the mean of its divisors is an integer number (55431660148011).

Almost surely, 2^{221201222012021} is an apocalyptic number.

It is an amenable number.

221201222012021 is a deficient number, since it is larger than the sum of its proper divisors (525418580023).

221201222012021 is an equidigital number, since it uses as much as digits as its factorization.

221201222012021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 525418580022.

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 221201222012021 its reverse (120210222102122), we get a palindrome (341411444114143).

The spelling of 221201222012021 in words is "two hundred twenty-one trillion, two hundred one billion, two hundred twenty-two million, twelve thousand, twenty-one".