1021056221 has 2 divisors, whose sum is σ = 1021056222. Its totient is φ = 1021056220.

The previous prime is 1021056191. The next prime is 1021056263. The reversal of 1021056221 is 1226501201.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 972753721 + 48302500 = 31189^2 + 6950^2 .

It is an emirp because it is prime and its reverse (1226501201) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1021056221 - 2¹⁰ = 1021055197 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1021056193 and 1021056202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1021056521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510528110 + 510528111.

It is an arithmetic number, because the mean of its divisors is an integer number (510528111).

Almost surely, 2^1021056221 is an apocalyptic number.

It is an amenable number.

1021056221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021056221 is an equidigital number, since it uses as much as digits as its factorization.

1021056221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 1021056221 is about 31953.9703479865. The cubic root of 1021056221 is about 1006.9700459213.

Adding to 1021056221 its reverse (1226501201), we get a palindrome (2247557422).

The spelling of 1021056221 in words is "one billion, twenty-one million, fifty-six thousand, two hundred twenty-one".