166813 has 4 divisors (see below), whose sum is σ = 168480. Its totient is φ = 165148.

The previous prime is 166807. The next prime is 166823. The reversal of 166813 is 318661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 318661 = 7 ⋅45523.

It is a cyclic number.

It is not a de Polignac number, because 166813 - 2⁵ = 166781 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166823) 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, 673 + ... + 886.

It is an arithmetic number, because the mean of its divisors is an integer number (42120).

2¹⁶⁶⁸¹³ is an apocalyptic number.

It is an amenable number.

166813 is a deficient number, since it is larger than the sum of its proper divisors (1667).

166813 is a wasteful number, since it uses less digits than its factorization.

166813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1666.

The product of its digits is 864, while the sum is 25.

The square root of 166813 is about 408.4274721416. The cubic root of 166813 is about 55.0482221709.

It can be divided in two parts, 1668 and 13, that added together give a square (1681 = 41²).

The spelling of 166813 in words is "one hundred sixty-six thousand, eight hundred thirteen".