665100001566 has 192 divisors, whose sum is σ = 1987131234816. Its totient is φ = 155154528000.

The previous prime is 665100001547. The next prime is 665100001589.

665100001566 is nontrivially palindromic in base 10.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 665100001566.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 167841 + ... + 1165491.

It is an arithmetic number, because the mean of its divisors is an integer number (10349641848).

Almost surely, 2^665100001566 is an apocalyptic number.

665100001566 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 665100001566, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (993565617408).

665100001566 is an abundant number, since it is smaller than the sum of its proper divisors (1322031233250).

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

665100001566 is a wasteful number, since it uses less digits than its factorization.

665100001566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 997727 (or 997724 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

It can be divided in two parts, 66510000 and 1566, that added together give a palindrome (66511566).

The spelling of 665100001566 in words is "six hundred sixty-five billion, one hundred million, one thousand, five hundred sixty-six".