1131778993 has 2 divisors, whose sum is σ = 1131778994. Its totient is φ = 1131778992.

The previous prime is 1131778957. The next prime is 1131778997. The reversal of 1131778993 is 3998771311.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 586463089 + 545315904 = 24217^2 + 23352^2 .

It is an emirp because it is prime and its reverse (3998771311) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1131778993 - 2⁹ = 1131778481 is a prime.

It is not a weakly prime, because it can be changed into another prime (1131778997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 565889496 + 565889497.

It is an arithmetic number, because the mean of its divisors is an integer number (565889497).

Almost surely, 2^1131778993 is an apocalyptic number.

It is an amenable number.

1131778993 is a deficient number, since it is larger than the sum of its proper divisors (1).

1131778993 is an equidigital number, since it uses as much as digits as its factorization.

1131778993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 285768, while the sum is 49.

The square root of 1131778993 is about 33641.9231465741. The cubic root of 1131778993 is about 1042.1267478564.

The spelling of 1131778993 in words is "one billion, one hundred thirty-one million, seven hundred seventy-eight thousand, nine hundred ninety-three".