6665106561660 has 384 divisors, whose sum is σ = 21546766080000. Its totient is φ = 1709039886336.

The previous prime is 6665106561559. The next prime is 6665106561661. The reversal of 6665106561660 is 661656015666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a junction number, because it is equal to n+sod(n) for n = 6665106561597 and 6665106561606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6665106561661) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1626030291 + ... + 1626034389.

It is an arithmetic number, because the mean of its divisors is an integer number (56111370000).

Almost surely, 2^{6665106561660} is an apocalyptic number.

6665106561660 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6665106561660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10773383040000).

6665106561660 is an abundant number, since it is smaller than the sum of its proper divisors (14881659518340).

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

6665106561660 is a wasteful number, since it uses less digits than its factorization.

6665106561660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5090 (or 5082 counting only the distinct ones).

The product of its (nonzero) digits is 6998400, while the sum is 54.

The spelling of 6665106561660 in words is "six trillion, six hundred sixty-five billion, one hundred six million, five hundred sixty-one thousand, six hundred sixty".