18668640424 has 32 divisors (see below), whose sum is σ = 40400323200. Its totient is φ = 7921627200.

The previous prime is 18668640421. The next prime is 18668640427. The reversal of 18668640424 is 42404686681.

It is an interprime number because it is at equal distance from previous prime (18668640421) and next prime (18668640427).

It is not an unprimeable number, because it can be changed into a prime (18668640421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1644684 + ... + 1655995.

It is an arithmetic number, because the mean of its divisors is an integer number (1262510100).

Almost surely, 2^18668640424 is an apocalyptic number.

18668640424 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

18668640424 is an abundant number, since it is smaller than the sum of its proper divisors (21731682776).

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

18668640424 is a wasteful number, since it uses less digits than its factorization.

18668640424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3300793 (or 3300789 counting only the distinct ones).

The product of its (nonzero) digits is 1769472, while the sum is 49.

The spelling of 18668640424 in words is "eighteen billion, six hundred sixty-eight million, six hundred forty thousand, four hundred twenty-four".