119991 has 16 divisors (see below), whose sum is σ = 175104. Its totient is φ = 72864.

The previous prime is 119983. The next prime is 119993. The reversal of 119991 is 199911.

119991 = T₄₈ + T₄₉ + ... + T₉₃.

It is not a de Polignac number, because 119991 - 2³ = 119983 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (119993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2530 + ... + 2576.

It is an arithmetic number, because the mean of its divisors is an integer number (10944).

2¹¹⁹⁹⁹¹ is an apocalyptic number.

119991 is a deficient number, since it is larger than the sum of its proper divisors (55113).

119991 is a wasteful number, since it uses less digits than its factorization.

119991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110.

The product of its digits is 729, while the sum is 30.

The square root of 119991 is about 346.3971708891. The cubic root of 119991 is about 49.3230083497.

Adding to 119991 its sum of digits (30), we get a palindrome (120021).

It can be divided in two parts, 11 and 9991, that multiplied together give a palindrome (109901).

The spelling of 119991 in words is "one hundred nineteen thousand, nine hundred ninety-one".