1311561230556 has 12 divisors (see below), whose sum is σ = 3060309537992. Its totient is φ = 437187076848.

The previous prime is 1311561230513. The next prime is 1311561230579. The reversal of 1311561230556 is 6550321651131.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×1311561230556² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 54648384595 + ... + 54648384618.

Almost surely, 2^{1311561230556} is an apocalyptic number.

It is an amenable number.

1311561230556 is an abundant number, since it is smaller than the sum of its proper divisors (1748748307436).

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

1311561230556 is a wasteful number, since it uses less digits than its factorization.

1311561230556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109296769220 (or 109296769218 counting only the distinct ones).

The product of its (nonzero) digits is 81000, while the sum is 39.

Adding to 1311561230556 its reverse (6550321651131), we get a palindrome (7861882881687).

The spelling of 1311561230556 in words is "one trillion, three hundred eleven billion, five hundred sixty-one million, two hundred thirty thousand, five hundred fifty-six".