18011391408 has 60 divisors (see below), whose sum is σ = 50905999248. Its totient is φ = 5944348800.

The previous prime is 18011391401. The next prime is 18011391443. The reversal of 18011391408 is 80419311081.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (18011391401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 604660 + ... + 633747.

Almost surely, 2^18011391408 is an apocalyptic number.

18011391408 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

18011391408 is an abundant number, since it is smaller than the sum of its proper divisors (32894607840).

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

18011391408 is a wasteful number, since it uses less digits than its factorization.

18011391408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1238522 (or 1238513 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 36.

The spelling of 18011391408 in words is "eighteen billion, eleven million, three hundred ninety-one thousand, four hundred eight".