11955811813 has 32 divisors (see below), whose sum is σ = 13582401408. Its totient is φ = 10428364800.

The previous prime is 11955811771. The next prime is 11955811873. The reversal of 11955811813 is 31811855911.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11955811813 is a prime.

It is a super-2 number, since 2×11955811813² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 11955811813.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11955811873) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 12236781 + ... + 12237757.

It is an arithmetic number, because the mean of its divisors is an integer number (424450044).

Almost surely, 2^11955811813 is an apocalyptic number.

It is an amenable number.

11955811813 is a deficient number, since it is larger than the sum of its proper divisors (1626589595).

11955811813 is a wasteful number, since it uses less digits than its factorization.

11955811813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1413.

The product of its digits is 43200, while the sum is 43.

The spelling of 11955811813 in words is "eleven billion, nine hundred fifty-five million, eight hundred eleven thousand, eight hundred thirteen".