665835538566 has 96 divisors (see below), whose sum is σ = 1607767499520. Its totient is φ = 182838047040.

The previous prime is 665835538523. The next prime is 665835538573.

665835538566 is nontrivially palindromic in base 10.

It is a Harshad number since it is a multiple of its sum of digits (66).

It is a junction number, because it is equal to n+sod(n) for n = 665835538497 and 665835538506.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 732085 + ... + 1366608.

It is an arithmetic number, because the mean of its divisors is an integer number (16747578120).

Almost surely, 2^665835538566 is an apocalyptic number.

665835538566 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

665835538566 is an abundant number, since it is smaller than the sum of its proper divisors (941931960954).

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

665835538566 is a wasteful number, since it uses less digits than its factorization.

665835538566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2098762 (or 2098751 counting only the distinct ones).

The product of its digits is 466560000, while the sum is 66.

The spelling of 665835538566 in words is "six hundred sixty-five billion, eight hundred thirty-five million, five hundred thirty-eight thousand, five hundred sixty-six".