12138172646 has 4 divisors (see below), whose sum is σ = 18207258972. Its totient is φ = 6069086322.

The previous prime is 12138172643. The next prime is 12138172663. The reversal of 12138172646 is 64627183121.

It is a semiprime because it is the product of two primes.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12138172643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3034543160 + ... + 3034543163.

It is an arithmetic number, because the mean of its divisors is an integer number (4551814743).

Almost surely, 2^12138172646 is an apocalyptic number.

12138172646 is a deficient number, since it is larger than the sum of its proper divisors (6069086326).

12138172646 is an equidigital number, since it uses as much as digits as its factorization.

12138172646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6069086325.

The product of its digits is 96768, while the sum is 41.

The spelling of 12138172646 in words is "twelve billion, one hundred thirty-eight million, one hundred seventy-two thousand, six hundred forty-six".