1665000 has 120 divisors (see below), whose sum is σ = 5787210. Its totient is φ = 432000.

The previous prime is 1664987. The next prime is 1665007. The reversal of 1665000 is 5661.

1665000 is a `hidden beast` number, since 1 + 665 + 0 + 0 + 0 = 666.

It can be written as a sum of positive squares in 5 ways, for example, as 181476 + 1483524 = 426^2 + 1218^2 .

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (1665007) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 44982 + ... + 45018.

2^1665000 is an apocalyptic number.

1665000 is a gapful number since it is divisible by the number (10) 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 1665000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2893605).

1665000 is an abundant number, since it is smaller than the sum of its proper divisors (4122210).

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

1665000 is a wasteful number, since it uses less digits than its factorization.

1665000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69 (or 47 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 1665000 is about 1290.3487900564. The cubic root of 1665000 is about 118.5235759319.

The spelling of 1665000 in words is "one million, six hundred sixty-five thousand".