201220212211221 has 16 divisors (see below), whose sum is σ = 306641347017344. Its totient is φ = 114975451681344.

The previous prime is 201220212211217. The next prime is 201220212211259. The reversal of 201220212211221 is 122112212022102.

It is not a de Polignac number, because 201220212211221 - 2² = 201220212211217 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201220212211261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 313285090 + ... + 313926723.

It is an arithmetic number, because the mean of its divisors is an integer number (19165084188584).

Almost surely, 2^{201220212211221} is an apocalyptic number.

201220212211221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

201220212211221 is a deficient number, since it is larger than the sum of its proper divisors (105421134806123).

201220212211221 is a wasteful number, since it uses less digits than its factorization.

201220212211221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 627227100.

The product of its (nonzero) digits is 256, while the sum is 21.

Adding to 201220212211221 its reverse (122112212022102), we get a palindrome (323332424233323).

The spelling of 201220212211221 in words is "two hundred one trillion, two hundred twenty billion, two hundred twelve million, two hundred eleven thousand, two hundred twenty-one".