11691878418 has 448 divisors, whose sum is σ = 33373399680. Its totient is φ = 3023308800.

The previous prime is 11691878417. The next prime is 11691878431. The reversal of 11691878418 is 81487819611.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (11691878417) by changing a digit.

It is a polite number, since it can be written in 223 ways as a sum of consecutive naturals, for example, 191670108 + ... + 191670168.

Almost surely, 2^11691878418 is an apocalyptic number.

11691878418 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 11691878418, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16686699840).

11691878418 is an abundant number, since it is smaller than the sum of its proper divisors (21681521262).

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

11691878418 is a wasteful number, since it uses less digits than its factorization.

11691878418 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165 (or 150 counting only the distinct ones).

The product of its digits is 774144, while the sum is 54.

The spelling of 11691878418 in words is "eleven billion, six hundred ninety-one million, eight hundred seventy-eight thousand, four hundred eighteen".