1021011021221 has 2 divisors, whose sum is σ = 1021011021222. Its totient is φ = 1021011021220.

The previous prime is 1021011021181. The next prime is 1021011021253. The reversal of 1021011021221 is 1221201101201.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1014391408900 + 6619612321 = 1007170^2 + 81361^2 .

It is an emirp because it is prime and its reverse (1221201101201) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1021011021221 - 2³⁰ = 1019937279397 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1021011021196 and 1021011021205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1021011021281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510505510610 + 510505510611.

It is an arithmetic number, because the mean of its divisors is an integer number (510505510611).

Almost surely, 2^{1021011021221} is an apocalyptic number.

It is an amenable number.

1021011021221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021011021221 is an equidigital number, since it uses as much as digits as its factorization.

1021011021221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 1021011021221 its reverse (1221201101201), we get a palindrome (2242212122422).

The spelling of 1021011021221 in words is "one trillion, twenty-one billion, eleven million, twenty-one thousand, two hundred twenty-one".