1311655680 has 216 divisors, whose sum is σ = 4707389232. Its totient is φ = 349691904.

The previous prime is 1311655679. The next prime is 1311655711. The reversal of 1311655680 is 865561131.

1311655680 is a `hidden beast` number, since 1 + 31 + 1 + 65 + 568 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (216).

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

It is a congruent number.

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, 308932 + ... + 313148.

Almost surely, 2^1311655680 is an apocalyptic number.

1311655680 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 1311655680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2353694616).

1311655680 is an abundant number, since it is smaller than the sum of its proper divisors (3395733552).

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

1311655680 is an frugal number, since it uses more digits than its factorization.

1311655680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4253 (or 4227 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 36.

The square root of 1311655680 is about 36216.7872677851. The cubic root of 1311655680 is about 1094.6449590173.

The spelling of 1311655680 in words is "one billion, three hundred eleven million, six hundred fifty-five thousand, six hundred eighty".