12311281440 has 144 divisors (see below), whose sum is σ = 42198444288. Its totient is φ = 3268459008.

The previous prime is 12311281427. The next prime is 12311281487. The reversal of 12311281440 is 4418211321.

It is a tau number, because it is divible by the number of its divisors (144).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 308049 + ... + 345711.

It is an arithmetic number, because the mean of its divisors is an integer number (293044752).

Almost surely, 2^12311281440 is an apocalyptic number.

12311281440 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 12311281440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21099222144).

12311281440 is an abundant number, since it is smaller than the sum of its proper divisors (29887162848).

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

12311281440 is a wasteful number, since it uses less digits than its factorization.

12311281440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37911 (or 37900 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

Adding to 12311281440 its reverse (4418211321), we get a palindrome (16729492761).

The spelling of 12311281440 in words is "twelve billion, three hundred eleven million, two hundred eighty-one thousand, four hundred forty".