1131891889 has 2 divisors, whose sum is σ = 1131891890. Its totient is φ = 1131891888.

The previous prime is 1131891857. The next prime is 1131891899. The reversal of 1131891889 is 9881981311.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 914034289 + 217857600 = 30233^2 + 14760^2 .

It is a cyclic number.

It is not a de Polignac number, because 1131891889 - 2⁵ = 1131891857 is a prime.

It is not a weakly prime, because it can be changed into another prime (1131891829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 565945944 + 565945945.

It is an arithmetic number, because the mean of its divisors is an integer number (565945945).

Almost surely, 2^1131891889 is an apocalyptic number.

It is an amenable number.

1131891889 is a deficient number, since it is larger than the sum of its proper divisors (1).

1131891889 is an equidigital number, since it uses as much as digits as its factorization.

1131891889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 124416, while the sum is 49.

The square root of 1131891889 is about 33643.6010111878. The cubic root of 1131891889 is about 1042.1613977396.

The spelling of 1131891889 in words is "one billion, one hundred thirty-one million, eight hundred ninety-one thousand, eight hundred eighty-nine".