168638 has 4 divisors (see below), whose sum is σ = 252960. Its totient is φ = 84318.

The previous prime is 168631. The next prime is 168643. The reversal of 168638 is 836861.

It is a semiprime because it is the product of two primes.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (168631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42158 + ... + 42161.

It is an arithmetic number, because the mean of its divisors is an integer number (63240).

2¹⁶⁸⁶³⁸ is an apocalyptic number.

168638 is a deficient number, since it is larger than the sum of its proper divisors (84322).

168638 is an equidigital number, since it uses as much as digits as its factorization.

168638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84321.

The product of its digits is 6912, while the sum is 32.

The square root of 168638 is about 410.6555734432. The cubic root of 168638 is about 55.2482442471.

The spelling of 168638 in words is "one hundred sixty-eight thousand, six hundred thirty-eight".