1091264021 has 2 divisors, whose sum is σ = 1091264022. Its totient is φ = 1091264020.

The previous prime is 1091263981. The next prime is 1091264039. The reversal of 1091264021 is 1204621901.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 928420900 + 162843121 = 30470^2 + 12761^2 .

It is a cyclic number.

It is not a de Polignac number, because 1091264021 - 2¹⁴ = 1091247637 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1091264071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 545632010 + 545632011.

It is an arithmetic number, because the mean of its divisors is an integer number (545632011).

Almost surely, 2^1091264021 is an apocalyptic number.

It is an amenable number.

1091264021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1091264021 is an equidigital number, since it uses as much as digits as its factorization.

1091264021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 1091264021 is about 33034.2855379074. The cubic root of 1091264021 is about 1029.5401287018.

Adding to 1091264021 its reverse (1204621901), we get a palindrome (2295885922).

The spelling of 1091264021 in words is "one billion, ninety-one million, two hundred sixty-four thousand, twenty-one".