166658278009 has 8 divisors (see below), whose sum is σ = 170734805640. Its totient is φ = 162582307200.

The previous prime is 166658277991. The next prime is 166658278109. The reversal of 166658278009 is 900872856661.

It can be written as a sum of positive squares in 4 ways, for example, as 9604588009 + 157053690000 = 98003^2 + 396300^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 166658278009 - 2⁹ = 166658277497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166658278109) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 502447 + ... + 765355.

It is an arithmetic number, because the mean of its divisors is an integer number (21341850705).

Almost surely, 2^166658278009 is an apocalyptic number.

It is an amenable number.

166658278009 is a deficient number, since it is larger than the sum of its proper divisors (4076527631).

166658278009 is a wasteful number, since it uses less digits than its factorization.

166658278009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278411.

The product of its (nonzero) digits is 8709120, while the sum is 58.

The spelling of 166658278009 in words is "one hundred sixty-six billion, six hundred fifty-eight million, two hundred seventy-eight thousand, nine".