11391405018 has 64 divisors (see below), whose sum is σ = 26897080320. Its totient is φ = 3147393600.

The previous prime is 11391405013. The next prime is 11391405019. The reversal of 11391405018 is 81050419311.

It is a self number, because there is not a number n which added to its sum of digits gives 11391405018.

It is not an unprimeable number, because it can be changed into a prime (11391405013) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2574448 + ... + 2578868.

It is an arithmetic number, because the mean of its divisors is an integer number (420266880).

Almost surely, 2^11391405018 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 11391405018, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13448540160).

11391405018 is an abundant number, since it is smaller than the sum of its proper divisors (15505675302).

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

11391405018 is a wasteful number, since it uses less digits than its factorization.

11391405018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6443.

The product of its (nonzero) digits is 4320, while the sum is 33.

The spelling of 11391405018 in words is "eleven billion, three hundred ninety-one million, four hundred five thousand, eighteen".