18307991424 has 128 divisors (see below), whose sum is σ = 54201657600. Its totient is φ = 5441347584.

The previous prime is 18307991389. The next prime is 18307991447. The reversal of 18307991424 is 42419970381.

It is a tau number, because it is divible by the number of its divisors (128).

It is a hoax number, since the sum of its digits (48) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50229 + ... + 197835.

It is an arithmetic number, because the mean of its divisors is an integer number (423450450).

Almost surely, 2^18307991424 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 18307991424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27100828800).

18307991424 is an abundant number, since it is smaller than the sum of its proper divisors (35893666176).

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

18307991424 is a wasteful number, since it uses less digits than its factorization.

18307991424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147660 (or 147648 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 48.

The spelling of 18307991424 in words is "eighteen billion, three hundred seven million, nine hundred ninety-one thousand, four hundred twenty-four".