1665288 has 48 divisors (see below), whose sum is σ = 4574700. Its totient is φ = 547200.

The previous prime is 1665277. The next prime is 1665311. The reversal of 1665288 is 8825661.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1205604 + 459684 = 1098^2 + 678^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7158 + ... + 7386.

2^1665288 is an apocalyptic number.

1665288 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1665288, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2287350).

1665288 is an abundant number, since it is smaller than the sum of its proper divisors (2909412).

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

1665288 is a wasteful number, since it uses less digits than its factorization.

1665288 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 342 (or 335 counting only the distinct ones).

The product of its digits is 23040, while the sum is 36.

The square root of 1665288 is about 1290.4603829642. The cubic root of 1665288 is about 118.5304093297.

It can be divided in two parts, 1665 and 288, that added together give a triangular number (1953 = T₆₂).

The spelling of 1665288 in words is "one million, six hundred sixty-five thousand, two hundred eighty-eight".