12181512831 has 4 divisors (see below), whose sum is σ = 16242017112. Its totient is φ = 8121008552.

The previous prime is 12181512823. The next prime is 12181512851. The reversal of 12181512831 is 13821518121.

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 12181512831 - 2³ = 12181512823 is a prime.

It is a super-2 number, since 2×12181512831² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 12181512792 and 12181512801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12181512851) 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, 2030252136 + ... + 2030252141.

It is an arithmetic number, because the mean of its divisors is an integer number (4060504278).

Almost surely, 2^12181512831 is an apocalyptic number.

12181512831 is a deficient number, since it is larger than the sum of its proper divisors (4060504281).

12181512831 is an equidigital number, since it uses as much as digits as its factorization.

12181512831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4060504280.

The product of its digits is 3840, while the sum is 33.

The spelling of 12181512831 in words is "twelve billion, one hundred eighty-one million, five hundred twelve thousand, eight hundred thirty-one".