166646 has 8 divisors (see below), whose sum is σ = 252840. Its totient is φ = 82368.

The previous prime is 166643. The next prime is 166657. The reversal of 166646 is 646661.

166646 = T₃ + T₄ + ... + T₉₉.

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

It is a plaindrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166643) 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, 236 + ... + 623.

It is an arithmetic number, because the mean of its divisors is an integer number (31605).

2¹⁶⁶⁶⁴⁶ is an apocalyptic number.

166646 is a deficient number, since it is larger than the sum of its proper divisors (86194).

166646 is an equidigital number, since it uses as much as digits as its factorization.

166646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 958.

The product of its digits is 5184, while the sum is 29.

The square root of 166646 is about 408.2229782852. Note that the first 3 decimals coincide. The cubic root of 166646 is about 55.0298460599.

It can be divided in two parts, 1666 and 46, that multiplied together give a triangular number (76636 = T₃₉₁).

The spelling of 166646 in words is "one hundred sixty-six thousand, six hundred forty-six".