221101011021221 has 2 divisors, whose sum is σ = 221101011021222. Its totient is φ = 221101011021220.

The previous prime is 221101011021097. The next prime is 221101011021257. The reversal of 221101011021221 is 122120110101122.

221101011021221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 124386866128996 + 96714144892225 = 11152886^2 + 9834335^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221101011021221 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221101011021221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221101011024221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110550505510610 + 110550505510611.

It is an arithmetic number, because the mean of its divisors is an integer number (110550505510611).

Almost surely, 2^{221101011021221} is an apocalyptic number.

It is an amenable number.

221101011021221 is a deficient number, since it is larger than the sum of its proper divisors (1).

221101011021221 is an equidigital number, since it uses as much as digits as its factorization.

221101011021221 is an evil number, because the sum of its binary digits is even.

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

Adding to 221101011021221 its reverse (122120110101122), we get a palindrome (343221121122343).

The spelling of 221101011021221 in words is "two hundred twenty-one trillion, one hundred one billion, eleven million, twenty-one thousand, two hundred twenty-one".