18139941666 has 96 divisors (see below), whose sum is σ = 49733019648. Its totient is φ = 4641325920.

The previous prime is 18139941661. The next prime is 18139941671. The reversal of 18139941666 is 66614993181.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18139941661) and next prime (18139941671).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18139941661) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4810 + ... + 190533.

It is an arithmetic number, because the mean of its divisors is an integer number (518052288).

Almost surely, 2^18139941666 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18139941666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24866509824).

18139941666 is an abundant number, since it is smaller than the sum of its proper divisors (31593077982).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18139941666 is a wasteful number, since it uses less digits than its factorization.

18139941666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195436 (or 195433 counting only the distinct ones).

The product of its digits is 1679616, while the sum is 54.

It can be divided in two parts, 18139 and 941666, that added together give a triangular number (959805 = T₁₃₈₅).

The spelling of 18139941666 in words is "eighteen billion, one hundred thirty-nine million, nine hundred forty-one thousand, six hundred sixty-six".