1131891197 has 2 divisors, whose sum is σ = 1131891198. Its totient is φ = 1131891196.

The previous prime is 1131891191. The next prime is 1131891217. The reversal of 1131891197 is 7911981311.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 750431236 + 381459961 = 27394^2 + 19531^2 .

It is a cyclic number.

It is not a de Polignac number, because 1131891197 - 2⁶ = 1131891133 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1131891191) 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, 565945598 + 565945599.

It is an arithmetic number, because the mean of its divisors is an integer number (565945599).

Almost surely, 2^1131891197 is an apocalyptic number.

It is an amenable number.

1131891197 is a deficient number, since it is larger than the sum of its proper divisors (1).

1131891197 is an equidigital number, since it uses as much as digits as its factorization.

1131891197 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13608, while the sum is 41.

The square root of 1131891197 is about 33643.5907269126. The cubic root of 1131891197 is about 1042.1611853589.

The spelling of 1131891197 in words is "one billion, one hundred thirty-one million, eight hundred ninety-one thousand, one hundred ninety-seven".