1311660840 has 256 divisors, whose sum is σ = 4916920320. Its totient is φ = 272977920.

The previous prime is 1311660827. The next prime is 1311660881. The reversal of 1311660840 is 480661131.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 1311660798 and 1311660807.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 441199 + ... + 444161.

It is an arithmetic number, because the mean of its divisors is an integer number (19206720).

Almost surely, 2^1311660840 is an apocalyptic number.

1311660840 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 1311660840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2458460160).

1311660840 is an abundant number, since it is smaller than the sum of its proper divisors (3605259480).

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

1311660840 is a wasteful number, since it uses less digits than its factorization.

1311660840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3032 (or 3028 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 1311660840 is about 36216.8585053977. The cubic root of 1311660840 is about 1094.6463944449.

The spelling of 1311660840 in words is "one billion, three hundred eleven million, six hundred sixty thousand, eight hundred forty".