1665444 has 72 divisors (see below), whose sum is σ = 4528384. Its totient is φ = 475200.

The previous prime is 1665437. The next prime is 1665451. The reversal of 1665444 is 4445661.

1665444 = 52² + 53² + ... + 172².

It is an interprime number because it is at equal distance from previous prime (1665437) and next prime (1665451).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 44994 + ... + 45030.

2^1665444 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 1665444, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2264192).

1665444 is an abundant number, since it is smaller than the sum of its proper divisors (2862940).

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

1665444 is a wasteful number, since it uses less digits than its factorization.

1665444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97 (or 84 counting only the distinct ones).

The product of its digits is 11520, while the sum is 30.

The square root of 1665444 is about 1290.5208250935. The cubic root of 1665444 is about 118.5341104246.

The spelling of 1665444 in words is "one million, six hundred sixty-five thousand, four hundred forty-four".