1131989 has 4 divisors (see below), whose sum is σ = 1134924. Its totient is φ = 1129056.

The previous prime is 1131973. The next prime is 1131997. The reversal of 1131989 is 9891311.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9891311 = 23 ⋅430057.

It can be written as a sum of positive squares in 2 ways, for example, as 792100 + 339889 = 890^2 + 583^2 .

It is a cyclic number.

It is not a de Polignac number, because 1131989 - 2⁴ = 1131973 is a prime.

It is a super-2 number, since 2×1131989² = 2562798192242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1131919) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 782 + ... + 1695.

It is an arithmetic number, because the mean of its divisors is an integer number (283731).

2^1131989 is an apocalyptic number.

It is an amenable number.

1131989 is a deficient number, since it is larger than the sum of its proper divisors (2935).

1131989 is an equidigital number, since it uses as much as digits as its factorization.

1131989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2934.

The product of its digits is 1944, while the sum is 32.

The square root of 1131989 is about 1063.9497168570. The cubic root of 1131989 is about 104.2191201069.

The spelling of 1131989 in words is "one million, one hundred thirty-one thousand, nine hundred eighty-nine".