1659904 has 22 divisors (see below), whose sum is σ = 3320234. Its totient is φ = 829440.

The previous prime is 1659893. The next prime is 1659913. The reversal of 1659904 is 4099561.

It can be written as a sum of positive squares in only one way, i.e., 1557504 + 102400 = 1248^2 + 320^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1659904.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 214 + ... + 1834.

2^1659904 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1659904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1660117).

1659904 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

1659904 is an equidigital number, since it uses as much as digits as its factorization.

1659904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1641 (or 1623 counting only the distinct ones).

The product of its (nonzero) digits is 9720, while the sum is 34.

The square root of 1659904 is about 1288.3726169086. The cubic root of 1659904 is about 118.4025322078.

The spelling of 1659904 in words is "one million, six hundred fifty-nine thousand, nine hundred four".