12156641280 has 504 divisors, whose sum is σ = 49093363332. Its totient is φ = 2774532096.

The previous prime is 12156641251. The next prime is 12156641291. The reversal of 12156641280 is 8214665121.

It is a happy number.

12156641280 is a `hidden beast` number, since 1 + 2 + 1 + 5 + 6 + 641 + 2 + 8 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 11851370496 + 305270784 = 108864^2 + 17472^2 .

It is a tau number, because it is divible by the number of its divisors (504).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 18063024 + ... + 18063696.

Almost surely, 2^12156641280 is an apocalyptic number.

12156641280 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 12156641280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24546681666).

12156641280 is an abundant number, since it is smaller than the sum of its proper divisors (36936722052).

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

12156641280 is an equidigital number, since it uses as much as digits as its factorization.

12156641280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 724 (or 690 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The spelling of 12156641280 in words is "twelve billion, one hundred fifty-six million, six hundred forty-one thousand, two hundred eighty".