3665704647609 has 9 divisors (see below), whose sum is σ = 5294915009839. Its totient is φ = 2443799269200.

The previous prime is 3665704647581. The next prime is 3665704647653. The reversal of 3665704647609 is 9067464075663.

The square root of 3665704647609 is 1914603.

It is a perfect power (a square), and thus also a powerful number.

3665704647609 is a `hidden beast` number, since 3 + 66 + 57 + 0 + 464 + 7 + 60 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1879632774009 + 1786071873600 = 1370997^2 + 1336440^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 3665704647609 - 2³³ = 3657114713017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3665704642609) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 5424709 + ... + 6062909.

Almost surely, 2^{3665704647609} is an apocalyptic number.

3665704647609 is the 1914603-rd square number.

3665704647609 is the 957302-nd centered octagonal number.

It is an amenable number.

3665704647609 is a deficient number, since it is larger than the sum of its proper divisors (1629210362230).

3665704647609 is an frugal number, since it uses more digits than its factorization.

3665704647609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1276408 (or 638204 counting only the distinct ones).

The product of its (nonzero) digits is 137168640, while the sum is 63.

The spelling of 3665704647609 in words is "three trillion, six hundred sixty-five billion, seven hundred four million, six hundred forty-seven thousand, six hundred nine".