1665564 has 12 divisors (see below), whose sum is σ = 3886344. Its totient is φ = 555184.

The previous prime is 1665563. The next prime is 1665569. The reversal of 1665564 is 4655661.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1665563) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 69387 + ... + 69410.

It is an arithmetic number, because the mean of its divisors is an integer number (323862).

2^1665564 is an apocalyptic number.

It is an amenable number.

1665564 is an abundant number, since it is smaller than the sum of its proper divisors (2220780).

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

1665564 is a wasteful number, since it uses less digits than its factorization.

1665564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138804 (or 138802 counting only the distinct ones).

The product of its digits is 21600, while the sum is 33.

The square root of 1665564 is about 1290.5673171129. The cubic root of 1665564 is about 118.5369572633.

The spelling of 1665564 in words is "one million, six hundred sixty-five thousand, five hundred sixty-four".