130991 has 4 divisors (see below), whose sum is σ = 149712. Its totient is φ = 112272.

The previous prime is 130987. The next prime is 131009. The reversal of 130991 is 199031.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 199031 = 7 ⋅28433.

It is a cyclic number.

It is not a de Polignac number, because 130991 - 2² = 130987 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (130981) 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, 9350 + ... + 9363.

It is an arithmetic number, because the mean of its divisors is an integer number (37428).

2¹³⁰⁹⁹¹ is an apocalyptic number.

130991 is a deficient number, since it is larger than the sum of its proper divisors (18721).

130991 is an equidigital number, since it uses as much as digits as its factorization.

130991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18720.

The product of its (nonzero) digits is 243, while the sum is 23.

The square root of 130991 is about 361.9267881768. The cubic root of 130991 is about 50.7863676815.

The spelling of 130991 in words is "one hundred thirty thousand, nine hundred ninety-one".