221101101021221 has 4 divisors (see below), whose sum is σ = 221101203498252. Its totient is φ = 221100998544192.

The previous prime is 221101101021197. The next prime is 221101101021253. The reversal of 221101101021221 is 122120101101122.

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 19206840918721 + 201894260102500 = 4382561^2 + 14208950^2 .

It is a cyclic number.

It is not a de Polignac number, because 221101101021221 - 2³⁴ = 221083921152037 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 221101101021221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221101101021271) 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, 47930996 + ... + 52341021.

It is an arithmetic number, because the mean of its divisors is an integer number (55275300874563).

Almost surely, 2^{221101101021221} is an apocalyptic number.

It is an amenable number.

221101101021221 is a deficient number, since it is larger than the sum of its proper divisors (102477031).

221101101021221 is a wasteful number, since it uses less digits than its factorization.

221101101021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102477030.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 221101101021221 its reverse (122120101101122), we get a palindrome (343221202122343).

The spelling of 221101101021221 in words is "two hundred twenty-one trillion, one hundred one billion, one hundred one million, twenty-one thousand, two hundred twenty-one".