12665621165340 has 384 divisors, whose sum is σ = 42119478116352. Its totient is φ = 2803326612480.

The previous prime is 12665621165311. The next prime is 12665621165389. The reversal of 12665621165340 is 4356112656621.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 12665621165340.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 762659317 + ... + 762675923.

It is an arithmetic number, because the mean of its divisors is an integer number (109686140928).

Almost surely, 2^{12665621165340} is an apocalyptic number.

12665621165340 is a gapful number since it is divisible by the number (10) 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 12665621165340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21059739058176).

12665621165340 is an abundant number, since it is smaller than the sum of its proper divisors (29453856951012).

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

12665621165340 is a wasteful number, since it uses less digits than its factorization.

12665621165340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17609 (or 17607 counting only the distinct ones).

The product of its (nonzero) digits is 1555200, while the sum is 48.

The spelling of 12665621165340 in words is "twelve trillion, six hundred sixty-five billion, six hundred twenty-one million, one hundred sixty-five thousand, three hundred forty".