12139731961 has 4 divisors (see below), whose sum is σ = 13873979392. Its totient is φ = 10405484532.

The previous prime is 12139731937. The next prime is 12139731979. The reversal of 12139731961 is 16913793121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 12139731961 - 2⁹ = 12139731449 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12139741961) 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, 867123705 + ... + 867123718.

It is an arithmetic number, because the mean of its divisors is an integer number (3468494848).

Almost surely, 2^12139731961 is an apocalyptic number.

It is an amenable number.

12139731961 is a deficient number, since it is larger than the sum of its proper divisors (1734247431).

12139731961 is an equidigital number, since it uses as much as digits as its factorization.

12139731961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1734247430.

The product of its digits is 61236, while the sum is 43.

The spelling of 12139731961 in words is "twelve billion, one hundred thirty-nine million, seven hundred thirty-one thousand, nine hundred sixty-one".