1091131973 has 2 divisors, whose sum is σ = 1091131974. Its totient is φ = 1091131972.

The previous prime is 1091131967. The next prime is 1091131991. The reversal of 1091131973 is 3791311901.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1073676289 + 17455684 = 32767^2 + 4178^2 .

It is a cyclic number.

It is not a de Polignac number, because 1091131973 - 2¹⁶ = 1091066437 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1091131903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 545565986 + 545565987.

It is an arithmetic number, because the mean of its divisors is an integer number (545565987).

Almost surely, 2^1091131973 is an apocalyptic number.

1091131973 is the 17657-th centered heptagonal number.

It is an amenable number.

1091131973 is a deficient number, since it is larger than the sum of its proper divisors (1).

1091131973 is an equidigital number, since it uses as much as digits as its factorization.

1091131973 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5103, while the sum is 35.

The square root of 1091131973 is about 33032.2868266791. The cubic root of 1091131973 is about 1029.4986006523.

The spelling of 1091131973 in words is "one billion, ninety-one million, one hundred thirty-one thousand, nine hundred seventy-three".