20121131091 has 8 divisors (see below), whose sum is σ = 27065592720. Its totient is φ = 13295378432.

The previous prime is 20121131059. The next prime is 20121131111. The reversal of 20121131091 is 19013112102.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20121131091 - 2⁵ = 20121131059 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20121131291) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29676846 + ... + 29677523.

It is an arithmetic number, because the mean of its divisors is an integer number (3383199090).

Almost surely, 2^20121131091 is an apocalyptic number.

20121131091 is a deficient number, since it is larger than the sum of its proper divisors (6944461629).

20121131091 is a wasteful number, since it uses less digits than its factorization.

20121131091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59354485.

The product of its (nonzero) digits is 108, while the sum is 21.

Adding to 20121131091 its reverse (19013112102), we get a palindrome (39134243193).

The spelling of 20121131091 in words is "twenty billion, one hundred twenty-one million, one hundred thirty-one thousand, ninety-one".