121831791 has 4 divisors (see below), whose sum is σ = 162442392. Its totient is φ = 81221192.

The previous prime is 121831769. The next prime is 121831793. The reversal of 121831791 is 197138121.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 121831791 - 2⁶ = 121831727 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121831793) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20305296 + ... + 20305301.

It is an arithmetic number, because the mean of its divisors is an integer number (40610598).

Almost surely, 2^121831791 is an apocalyptic number.

121831791 is a deficient number, since it is larger than the sum of its proper divisors (40610601).

121831791 is an equidigital number, since it uses as much as digits as its factorization.

121831791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40610600.

The product of its digits is 3024, while the sum is 33.

The square root of 121831791 is about 11037.7439270894. The cubic root of 121831791 is about 495.7395210853.

The spelling of 121831791 in words is "one hundred twenty-one million, eight hundred thirty-one thousand, seven hundred ninety-one".