13889166661 has 4 divisors (see below), whose sum is σ = 14079429292. Its totient is φ = 13698904032.

The previous prime is 13889166647. The next prime is 13889166673. The reversal of 13889166661 is 16666198831.

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: 16666198831 = 30841 ⋅540391.

It can be written as a sum of positive squares in 2 ways, for example, as 2532001761 + 11357164900 = 50319^2 + 106570^2 .

It is a cyclic number.

It is not a de Polignac number, because 13889166661 - 2⁹ = 13889166149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13889166761) 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, 95131206 + ... + 95131351.

It is an arithmetic number, because the mean of its divisors is an integer number (3519857323).

Almost surely, 2^13889166661 is an apocalyptic number.

It is an amenable number.

13889166661 is a deficient number, since it is larger than the sum of its proper divisors (190262631).

13889166661 is an equidigital number, since it uses as much as digits as its factorization.

13889166661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 190262630.

The product of its digits is 2239488, while the sum is 55.

The spelling of 13889166661 in words is "thirteen billion, eight hundred eighty-nine million, one hundred sixty-six thousand, six hundred sixty-one".