11812731638 has 4 divisors (see below), whose sum is σ = 17719097460. Its totient is φ = 5906365818.

The previous prime is 11812731631. The next prime is 11812731647. The reversal of 11812731638 is 83613721811.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83613721811 = 61 ⋅1370716751.

It is a junction number, because it is equal to n+sod(n) for n = 11812731595 and 11812731604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11812731631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2953182908 + ... + 2953182911.

It is an arithmetic number, because the mean of its divisors is an integer number (4429774365).

Almost surely, 2^11812731638 is an apocalyptic number.

11812731638 is a deficient number, since it is larger than the sum of its proper divisors (5906365822).

11812731638 is an equidigital number, since it uses as much as digits as its factorization.

11812731638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5906365821.

The product of its digits is 48384, while the sum is 41.

The spelling of 11812731638 in words is "eleven billion, eight hundred twelve million, seven hundred thirty-one thousand, six hundred thirty-eight".