19821328398 has 40 divisors (see below), whose sum is σ = 47027079792. Its totient is φ = 6218455104.

The previous prime is 19821328393. The next prime is 19821328427. The reversal of 19821328398 is 89382312891.

19821328398 is a `hidden beast` number, since 19 + 8 + 213 + 28 + 398 = 666.

It is a super-2 number, since 2×19821328398² (a number of 21 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (54) 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 (54).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19821328393) 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 19 ways as a sum of consecutive naturals, for example, 3595890 + ... + 3601397.

Almost surely, 2^19821328398 is an apocalyptic number.

19821328398 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

19821328398 is an abundant number, since it is smaller than the sum of its proper divisors (27205751394).

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

19821328398 is a wasteful number, since it uses less digits than its factorization.

19821328398 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7197318 (or 7197309 counting only the distinct ones).

The product of its digits is 1492992, while the sum is 54.

The spelling of 19821328398 in words is "nineteen billion, eight hundred twenty-one million, three hundred twenty-eight thousand, three hundred ninety-eight".