15665605665 has 8 divisors (see below), whose sum is σ = 25064969088. Its totient is φ = 8354989680.

The previous prime is 15665605619. The next prime is 15665605667. The reversal of 15665605665 is 56650656651.

15665605665 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 15665605665 - 2¹⁸ = 15665343521 is a prime.

It is a super-2 number, since 2×15665605665² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (15665605667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 522186841 + ... + 522186870.

It is an arithmetic number, because the mean of its divisors is an integer number (3133121136).

Almost surely, 2^15665605665 is an apocalyptic number.

15665605665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

15665605665 is a deficient number, since it is larger than the sum of its proper divisors (9399363423).

15665605665 is a wasteful number, since it uses less digits than its factorization.

15665605665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1044373719.

The product of its (nonzero) digits is 4860000, while the sum is 51.

The spelling of 15665605665 in words is "fifteen billion, six hundred sixty-five million, six hundred five thousand, six hundred sixty-five".