166138578789 has 8 divisors (see below), whose sum is σ = 221522578560. Its totient is φ = 110756815776.

The previous prime is 166138578769. The next prime is 166138578791. The reversal of 166138578789 is 987875831661.

166138578789 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 166138578789 - 2¹¹ = 166138576741 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166138578769) 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 in 7 ways as a sum of consecutive naturals, for example, 377437 + ... + 689010.

It is an arithmetic number, because the mean of its divisors is an integer number (27690322320).

Almost surely, 2^166138578789 is an apocalyptic number.

It is an amenable number.

166138578789 is a deficient number, since it is larger than the sum of its proper divisors (55383999771).

166138578789 is a wasteful number, since it uses less digits than its factorization.

166138578789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1118379.

The product of its digits is 121927680, while the sum is 69.

The spelling of 166138578789 in words is "one hundred sixty-six billion, one hundred thirty-eight million, five hundred seventy-eight thousand, seven hundred eighty-nine".