168990 has 32 divisors (see below), whose sum is σ = 418176. Its totient is φ = 43680.

The previous prime is 168977. The next prime is 168991. The reversal of 168990 is 99861.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (168991) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1225 + ... + 1355.

It is an arithmetic number, because the mean of its divisors is an integer number (13068).

2¹⁶⁸⁹⁹⁰ is an apocalyptic number.

168990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 168990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (209088).

168990 is an abundant number, since it is smaller than the sum of its proper divisors (249186).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

168990 is a wasteful number, since it uses less digits than its factorization.

168990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 184.

The product of its (nonzero) digits is 3888, while the sum is 33.

The square root of 168990 is about 411.0839330356. The cubic root of 168990 is about 55.2866576272.

The spelling of 168990 in words is "one hundred sixty-eight thousand, nine hundred ninety".