221220102101221 has 4 divisors (see below), whose sum is σ = 221220340304332. Its totient is φ = 221219863898112.

The previous prime is 221220102101203. The next prime is 221220102101239. The reversal of 221220102101221 is 122101201022122.

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

It is an interprime number because it is at equal distance from previous prime (221220102101203) and next prime (221220102101239).

It can be written as a sum of positive squares in 2 ways, for example, as 38152734704100 + 183067367397121 = 6176790^2 + 13530239^2 .

It is a cyclic number.

It is not a de Polignac number, because 221220102101221 - 2¹⁹ = 221220101576933 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221220102101521) 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 3 ways as a sum of consecutive naturals, for example, 117703026 + ... + 119567731.

It is an arithmetic number, because the mean of its divisors is an integer number (55305085076083).

Almost surely, 2^{221220102101221} is an apocalyptic number.

It is an amenable number.

221220102101221 is a deficient number, since it is larger than the sum of its proper divisors (238203111).

221220102101221 is an equidigital number, since it uses as much as digits as its factorization.

221220102101221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 238203110.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 221220102101221 its reverse (122101201022122), we get a palindrome (343321303123343).

The spelling of 221220102101221 in words is "two hundred twenty-one trillion, two hundred twenty billion, one hundred two million, one hundred one thousand, two hundred twenty-one".