1665564613504 has 64 divisors (see below), whose sum is σ = 3619998604800. Its totient is φ = 757025758720.

The previous prime is 1665564613499. The next prime is 1665564613511. The reversal of 1665564613504 is 4053164655661.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30113427 + ... + 30168685.

It is an arithmetic number, because the mean of its divisors is an integer number (56562478200).

Almost surely, 2^{1665564613504} is an apocalyptic number.

It is an amenable number.

1665564613504 is an abundant number, since it is smaller than the sum of its proper divisors (1954433991296).

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

1665564613504 is a wasteful number, since it uses less digits than its factorization.

1665564613504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76691 (or 76679 counting only the distinct ones).

The product of its (nonzero) digits is 7776000, while the sum is 52.

The spelling of 1665564613504 in words is "one trillion, six hundred sixty-five billion, five hundred sixty-four million, six hundred thirteen thousand, five hundred four".