12543661312 has 324 divisors, whose sum is σ = 32386544316. Its totient is φ = 4830658560.

The previous prime is 12543661303. The next prime is 12543661313. The reversal of 12543661312 is 21316634521.

It can be written as a sum of positive squares in 6 ways, for example, as 5431100416 + 7112560896 = 73696^2 + 84336^2 .

It is a super-2 number, since 2×12543661312² (a number of 21 digits) contains 22 as substring.

Its product of digits (25920) is a multiple of the sum of its prime divisors (180).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12543661313) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 129316048 + ... + 129316144.

Almost surely, 2^12543661312 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12543661312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16193272158).

12543661312 is an abundant number, since it is smaller than the sum of its proper divisors (19842883004).

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

12543661312 is an equidigital number, since it uses as much as digits as its factorization.

12543661312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214 (or 180 counting only the distinct ones).

The product of its digits is 25920, while the sum is 34.

The spelling of 12543661312 in words is "twelve billion, five hundred forty-three million, six hundred sixty-one thousand, three hundred twelve".