12861261864 has 128 divisors (see below), whose sum is σ = 40027132800. Its totient is φ = 3791992320.

The previous prime is 12861261839. The next prime is 12861261883. The reversal of 12861261864 is 46816216821.

It is a happy number.

12861261864 is a `hidden beast` number, since 1 + 28 + 6 + 1 + 2 + 618 + 6 + 4 = 666.

12861261864 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×12861261864³ (a number of 31 digits) contains 333 as substring.

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 14764 + ... + 161060.

It is an arithmetic number, because the mean of its divisors is an integer number (312711975).

Almost surely, 2^12861261864 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 12861261864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20013566400).

12861261864 is an abundant number, since it is smaller than the sum of its proper divisors (27165870936).

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

12861261864 is a wasteful number, since it uses less digits than its factorization.

12861261864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146360 (or 146350 counting only the distinct ones).

The product of its digits is 221184, while the sum is 45.

The spelling of 12861261864 in words is "twelve billion, eight hundred sixty-one million, two hundred sixty-one thousand, eight hundred sixty-four".