1665505656 has 24 divisors (see below), whose sum is σ = 4510744680. Its totient is φ = 555168528.

The previous prime is 1665505643. The next prime is 1665505663. The reversal of 1665505656 is 6565055661.

It is a tau number, because it is divible by the number of its divisors (24).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11565940 + ... + 11566083.

It is an arithmetic number, because the mean of its divisors is an integer number (187947695).

Almost surely, 2^1665505656 is an apocalyptic number.

It is an amenable number.

1665505656 is an abundant number, since it is smaller than the sum of its proper divisors (2845239024).

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

1665505656 is a wasteful number, since it uses less digits than its factorization.

1665505656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23132035 (or 23132028 counting only the distinct ones).

The product of its (nonzero) digits is 810000, while the sum is 45.

The square root of 1665505656 is about 40810.6071505926. The cubic root of 1665505656 is about 1185.3557314742.

The spelling of 1665505656 in words is "one billion, six hundred sixty-five million, five hundred five thousand, six hundred fifty-six".