1659 has 8 divisors (see below), whose sum is σ = 2560. Its totient is φ = 936.

The previous prime is 1657. The next prime is 1663. The reversal of 1659 is 9561.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1659 - 2¹ = 1657 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 79 = 1659 / (1 + 6 + 5 + 9).

It is a Duffinian number.

1659 is a lucky number.

It is a plaindrome in base 11 and base 16.

It is a nialpdrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1657) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19 + ... + 60.

It is an arithmetic number, because the mean of its divisors is an integer number (320).

1659 is a deficient number, since it is larger than the sum of its proper divisors (901).

1659 is an equidigital number, since it uses as much as digits as its factorization.

1659 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89.

The product of its digits is 270, while the sum is 21.

The square root of 1659 is about 40.7308237088. The cubic root of 1659 is about 11.8381033911.

It can be divided in two parts, 165 and 9, that multiplied together give a triangular number (1485 = T₅₄).

The spelling of 1659 in words is "one thousand, six hundred fifty-nine".