166890 has 16 divisors (see below), whose sum is σ = 400608. Its totient is φ = 44496.

The previous prime is 166871. The next prime is 166909. The reversal of 166890 is 98661.

It is an interprime number because it is at equal distance from previous prime (166871) and next prime (166909).

It is a Harshad number since it is a multiple of its sum of digits (30), and also a Moran number because the ratio is a prime number: 5563 = 166890 / (1 + 6 + 6 + 8 + 9 + 0).

It is an unprimeable number.

166890 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2752 + ... + 2811.

It is an arithmetic number, because the mean of its divisors is an integer number (25038).

2¹⁶⁶⁸⁹⁰ is an apocalyptic number.

166890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

166890 is an abundant number, since it is smaller than the sum of its proper divisors (233718).

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

166890 is a wasteful number, since it uses less digits than its factorization.

166890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5573.

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 166890 is about 408.5217252485. The cubic root of 166890 is about 55.0566908575.

The spelling of 166890 in words is "one hundred sixty-six thousand, eight hundred ninety".