166438 has 4 divisors (see below), whose sum is σ = 249660. Its totient is φ = 83218.

The previous prime is 166429. The next prime is 166457. The reversal of 166438 is 834661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 834661 = 317 ⋅2633.

It is a plaindrome in base 15.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41608 + ... + 41611.

It is an arithmetic number, because the mean of its divisors is an integer number (62415).

2¹⁶⁶⁴³⁸ is an apocalyptic number.

166438 is a deficient number, since it is larger than the sum of its proper divisors (83222).

166438 is an equidigital number, since it uses as much as digits as its factorization.

166438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83221.

The product of its digits is 3456, while the sum is 28.

The square root of 166438 is about 407.9681360106. The cubic root of 166438 is about 55.0069412727.

The spelling of 166438 in words is "one hundred sixty-six thousand, four hundred thirty-eight".