18723640320 has 704 divisors, whose sum is σ = 83006668800. Its totient is φ = 3888414720.

The previous prime is 18723640289. The next prime is 18723640339. The reversal of 18723640320 is 2304632781.

It is a happy number.

18723640320 is a `hidden beast` number, since 1 + 8 + 7 + 2 + 3 + 640 + 3 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (704).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 10643601 + ... + 10645359.

It is an arithmetic number, because the mean of its divisors is an integer number (117907200).

Almost surely, 2^18723640320 is an apocalyptic number.

18723640320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18723640320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41503334400).

18723640320 is an abundant number, since it is smaller than the sum of its proper divisors (64283028480).

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

18723640320 is a wasteful number, since it uses less digits than its factorization.

18723640320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1811 (or 1787 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 36.

The spelling of 18723640320 in words is "eighteen billion, seven hundred twenty-three million, six hundred forty thousand, three hundred twenty".