121791 has 4 divisors (see below), whose sum is σ = 162392. Its totient is φ = 81192.

The previous prime is 121789. The next prime is 121843. The reversal of 121791 is 197121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 197121 = 3 ⋅65707.

It is not a de Polignac number, because 121791 - 2¹ = 121789 is a prime.

It is a D-number.

It is a Duffinian number.

121791 is a lucky number.

It is a plaindrome in base 8.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121711) 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, 20296 + ... + 20301.

It is an arithmetic number, because the mean of its divisors is an integer number (40598).

2¹²¹⁷⁹¹ is an apocalyptic number.

121791 is a deficient number, since it is larger than the sum of its proper divisors (40601).

121791 is an equidigital number, since it uses as much as digits as its factorization.

121791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40600.

The product of its digits is 126, while the sum is 21.

The square root of 121791 is about 348.9856730584. The cubic root of 121791 is about 49.5684188051.

The spelling of 121791 in words is "one hundred twenty-one thousand, seven hundred ninety-one".