1311256656 has 30 divisors (see below), whose sum is σ = 3669697850. Its totient is φ = 437085504.

The previous prime is 1311256649. The next prime is 1311256673. The reversal of 1311256656 is 6566521131.

1311256656 is a `hidden beast` number, since 1 + 31 + 12 + 566 + 56 = 666.

It can be written as a sum of positive squares in only one way, i.e., 795240000 + 516016656 = 28200^2 + 22716^2 .

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

It is a self number, because there is not a number n which added to its sum of digits gives 1311256656.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4552831 + ... + 4553118.

Almost surely, 2^1311256656 is an apocalyptic number.

1311256656 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1311256656 is an abundant number, since it is smaller than the sum of its proper divisors (2358441194).

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

1311256656 is a wasteful number, since it uses less digits than its factorization.

1311256656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9105963 (or 9105954 counting only the distinct ones).

The product of its digits is 32400, while the sum is 36.

The square root of 1311256656 is about 36211.2780221853. The cubic root of 1311256656 is about 1094.5339456579.

Adding to 1311256656 its reverse (6566521131), we get a palindrome (7877777787).

The spelling of 1311256656 in words is "one billion, three hundred eleven million, two hundred fifty-six thousand, six hundred fifty-six".