1021320191 has 2 divisors, whose sum is σ = 1021320192. Its totient is φ = 1021320190.

The previous prime is 1021320143. The next prime is 1021320217. The reversal of 1021320191 is 1910231201.

It is a strong prime.

It is an emirp because it is prime and its reverse (1910231201) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1021320191 - 2¹⁸ = 1021058047 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1021320491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510660095 + 510660096.

It is an arithmetic number, because the mean of its divisors is an integer number (510660096).

Almost surely, 2^1021320191 is an apocalyptic number.

1021320191 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021320191 is an equidigital number, since it uses as much as digits as its factorization.

1021320191 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108, while the sum is 20.

The square root of 1021320191 is about 31958.1005536937. The cubic root of 1021320191 is about 1007.0568145617.

Adding to 1021320191 its reverse (1910231201), we get a palindrome (2931551392).

The spelling of 1021320191 in words is "one billion, twenty-one million, three hundred twenty thousand, one hundred ninety-one".