221220100010221 has 16 divisors (see below), whose sum is σ = 242187965071920. Its totient is φ = 200817909688320.

The previous prime is 221220100010209. The next prime is 221220100010233. The reversal of 221220100010221 is 122010001022122.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (221220100010209) and next prime (221220100010233).

It can be written as a sum of positive squares in 8 ways, for example, as 703124175625 + 220516975834596 = 838525^2 + 14849814^2 .

It is a cyclic number.

It is not a de Polignac number, because 221220100010221 - 2¹⁹ = 221220099485933 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221220100010195 and 221220100010204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221220100010321) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21925636 + ... + 30383773.

It is an arithmetic number, because the mean of its divisors is an integer number (15136747816995).

Almost surely, 2^{221220100010221} is an apocalyptic number.

It is an amenable number.

221220100010221 is a deficient number, since it is larger than the sum of its proper divisors (20967865061699).

221220100010221 is a wasteful number, since it uses less digits than its factorization.

221220100010221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52314816.

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

Adding to 221220100010221 its reverse (122010001022122), we get a palindrome (343230101032343).

It can be divided in two parts, 22 and 1220100010221, that multiplied together give a palindrome (26842200224862).

The spelling of 221220100010221 in words is "two hundred twenty-one trillion, two hundred twenty billion, one hundred million, ten thousand, two hundred twenty-one".