12129668640 has 288 divisors, whose sum is σ = 43952506416. Its totient is φ = 3035627520.

The previous prime is 12129668633. The next prime is 12129668641. The reversal of 12129668640 is 4686692121.

It can be written as a sum of positive squares in 8 ways, for example, as 6617497104 + 5512171536 = 81348^2 + 74244^2 .

It is a tau number, because it is divible by the number of its divisors (288).

It is a super-2 number, since 2×12129668640² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (12129668641) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 15691294 + ... + 15692066.

Almost surely, 2^12129668640 is an apocalyptic number.

12129668640 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 12129668640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21976253208).

12129668640 is an abundant number, since it is smaller than the sum of its proper divisors (31822837776).

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

12129668640 is a wasteful number, since it uses less digits than its factorization.

12129668640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1452 (or 1441 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 45.

The spelling of 12129668640 in words is "twelve billion, one hundred twenty-nine million, six hundred sixty-eight thousand, six hundred forty".