19997240328 has 96 divisors (see below), whose sum is σ = 58683555840. Its totient is φ = 6115201920.

The previous prime is 19997240321. The next prime is 19997240423. The reversal of 19997240328 is 82304279991.

19997240328 is a `hidden beast` number, since 199 + 97 + 2 + 40 + 328 = 666.

It is not an unprimeable number, because it can be changed into a prime (19997240321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 87033 + ... + 218103.

It is an arithmetic number, because the mean of its divisors is an integer number (611287040).

Almost surely, 2^19997240328 is an apocalyptic number.

19997240328 is a gapful number since it is divisible by the number (18) 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 19997240328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29341777920).

19997240328 is an abundant number, since it is smaller than the sum of its proper divisors (38686315512).

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

19997240328 is a wasteful number, since it uses less digits than its factorization.

19997240328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131259 (or 131252 counting only the distinct ones).

The product of its (nonzero) digits is 1959552, while the sum is 54.

The spelling of 19997240328 in words is "nineteen billion, nine hundred ninety-seven million, two hundred forty thousand, three hundred twenty-eight".