166139 has 4 divisors (see below), whose sum is σ = 167856. Its totient is φ = 164424.

The previous prime is 166099. The next prime is 166147. The reversal of 166139 is 931661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 931661 = 23 ⋅40507.

It is a cyclic number.

It is not a de Polignac number, because 166139 - 2⁸ = 165883 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 166139.

It is not an unprimeable number, because it can be changed into a prime (166169) 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, 704 + ... + 909.

It is an arithmetic number, because the mean of its divisors is an integer number (41964).

2¹⁶⁶¹³⁹ is an apocalyptic number.

166139 is a deficient number, since it is larger than the sum of its proper divisors (1717).

166139 is a wasteful number, since it uses less digits than its factorization.

166139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1716.

The product of its digits is 972, while the sum is 26.

The square root of 166139 is about 407.6015210963. The cubic root of 166139 is about 54.9739821845.

The spelling of 166139 in words is "one hundred sixty-six thousand, one hundred thirty-nine".