11985691648 has 132 divisors (see below), whose sum is σ = 28836048060. Its totient is φ = 4958994432.

The previous prime is 11985691643. The next prime is 11985691709. The reversal of 11985691648 is 84619658911.

It can be written as a sum of positive squares in 2 ways, for example, as 6943555584 + 5042136064 = 83328^2 + 71008^2 .

It is a Harshad number since it is a multiple of its sum of digits (58).

It is a junction number, because it is equal to n+sod(n) for n = 11985691592 and 11985691601.

It is not an unprimeable number, because it can be changed into a prime (11985691643) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1450986 + ... + 1459222.

Almost surely, 2^11985691648 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 11985691648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14418024030).

11985691648 is an abundant number, since it is smaller than the sum of its proper divisors (16850356412).

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

11985691648 is an equidigital number, since it uses as much as digits as its factorization.

11985691648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8300 (or 8275 counting only the distinct ones).

The product of its digits is 3732480, while the sum is 58.

The spelling of 11985691648 in words is "eleven billion, nine hundred eighty-five million, six hundred ninety-one thousand, six hundred forty-eight".