1165989 has 16 divisors (see below), whose sum is σ = 1719360. Its totient is φ = 696960.

The previous prime is 1165951. The next prime is 1165991. The reversal of 1165989 is 9895611.

It is not a de Polignac number, because 1165989 - 2⁷ = 1165861 is a prime.

It is a plaindrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1165909) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2739 + ... + 3135.

It is an arithmetic number, because the mean of its divisors is an integer number (107460).

2^1165989 is an apocalyptic number.

It is an amenable number.

1165989 is a deficient number, since it is larger than the sum of its proper divisors (553371).

1165989 is a wasteful number, since it uses less digits than its factorization.

1165989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 500.

The product of its digits is 19440, while the sum is 39.

The square root of 1165989 is about 1079.8097054574. The cubic root of 1165989 is about 105.2522732210.

It can be divided in two parts, 116 and 5989, that added together give a triangular number (6105 = T₁₁₀).

The spelling of 1165989 in words is "one million, one hundred sixty-five thousand, nine hundred eighty-nine".