12891206731 has 4 divisors (see below), whose sum is σ = 13882838032. Its totient is φ = 11899575432.

The previous prime is 12891206693. The next prime is 12891206747. The reversal of 12891206731 is 13760219821.

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 12891206731 - 2⁹ = 12891206219 is a prime.

It is a super-2 number, since 2×12891206731² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12891006731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 495815631 + ... + 495815656.

It is an arithmetic number, because the mean of its divisors is an integer number (3470709508).

Almost surely, 2^12891206731 is an apocalyptic number.

12891206731 is a deficient number, since it is larger than the sum of its proper divisors (991631301).

12891206731 is an equidigital number, since it uses as much as digits as its factorization.

12891206731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 991631300.

The product of its (nonzero) digits is 36288, while the sum is 40.

The spelling of 12891206731 in words is "twelve billion, eight hundred ninety-one million, two hundred six thousand, seven hundred thirty-one".