1221101012221 has 2 divisors, whose sum is σ = 1221101012222. Its totient is φ = 1221101012220.

The previous prime is 1221101012107. The next prime is 1221101012249. The reversal of 1221101012221 is 1222101011221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 960378440121 + 260722572100 = 979989^2 + 510610^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221101012221 - 2²⁷ = 1220966794493 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1221101012195 and 1221101012204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221101010221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610550506110 + 610550506111.

It is an arithmetic number, because the mean of its divisors is an integer number (610550506111).

Almost surely, 2^{1221101012221} is an apocalyptic number.

It is an amenable number.

1221101012221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221101012221 is an equidigital number, since it uses as much as digits as its factorization.

1221101012221 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 16.

Adding to 1221101012221 its reverse (1222101011221), we get a palindrome (2443202023442).

The spelling of 1221101012221 in words is "one trillion, two hundred twenty-one billion, one hundred one million, twelve thousand, two hundred twenty-one".