20123111231 has 8 divisors (see below), whose sum is σ = 20745224304. Its totient is φ = 19507250880.

The previous prime is 20123111213. The next prime is 20123111237. The reversal of 20123111231 is 13211132102.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20123111231 is a prime.

It is a super-2 number, since 2×20123111231² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20123111237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1556645 + ... + 1569518.

It is an arithmetic number, because the mean of its divisors is an integer number (2593153038).

Almost surely, 2^20123111231 is an apocalyptic number.

20123111231 is a deficient number, since it is larger than the sum of its proper divisors (622113073).

20123111231 is a wasteful number, since it uses less digits than its factorization.

20123111231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3126361.

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 20123111231 its reverse (13211132102), we get a palindrome (33334243333).

The spelling of 20123111231 in words is "twenty billion, one hundred twenty-three million, one hundred eleven thousand, two hundred thirty-one".