13166506642 has 4 divisors (see below), whose sum is σ = 19749759966. Its totient is φ = 6583253320.

The previous prime is 13166506621. The next prime is 13166506649. The reversal of 13166506642 is 24660566131.

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

It can be written as a sum of positive squares in only one way, i.e., 12327882961 + 838623681 = 111031^2 + 28959^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 13166506595 and 13166506604.

It is not an unprimeable number, because it can be changed into a prime (13166506649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3291626659 + ... + 3291626662.

Almost surely, 2^13166506642 is an apocalyptic number.

13166506642 is a deficient number, since it is larger than the sum of its proper divisors (6583253324).

13166506642 is an equidigital number, since it uses as much as digits as its factorization.

13166506642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6583253323.

The product of its (nonzero) digits is 155520, while the sum is 40.

The spelling of 13166506642 in words is "thirteen billion, one hundred sixty-six million, five hundred six thousand, six hundred forty-two".