166405 has 8 divisors (see below), whose sum is σ = 208512. Its totient is φ = 127248.

The previous prime is 166403. The next prime is 166409. The reversal of 166405 is 504661.

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 166405 - 2¹ = 166403 is a prime.

It is a Duffinian number.

It is a plaindrome in base 15.

It is a nialpdrome in base 6.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166403) 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, 609 + ... + 838.

It is an arithmetic number, because the mean of its divisors is an integer number (26064).

2¹⁶⁶⁴⁰⁵ is an apocalyptic number.

It is an amenable number.

166405 is a deficient number, since it is larger than the sum of its proper divisors (42107).

166405 is a wasteful number, since it uses less digits than its factorization.

166405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1475.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 166405 is about 407.9276896706. The cubic root of 166405 is about 55.0033055864.

The spelling of 166405 in words is "one hundred sixty-six thousand, four hundred five".