19821328453 has 4 divisors (see below), whose sum is σ = 19855681420. Its totient is φ = 19786975488.

The previous prime is 19821328433. The next prime is 19821328459. The reversal of 19821328453 is 35482312891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 35482312891 = 397 ⋅89376103.

It can be written as a sum of positive squares in 2 ways, for example, as 12320556004 + 7500772449 = 110998^2 + 86607^2 .

It is a cyclic number.

It is not a de Polignac number, because 19821328453 - 2²⁹ = 19284457541 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19821328459) 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 3 ways as a sum of consecutive naturals, for example, 17175618 + ... + 17176771.

It is an arithmetic number, because the mean of its divisors is an integer number (4963920355).

Almost surely, 2^19821328453 is an apocalyptic number.

It is an amenable number.

19821328453 is a deficient number, since it is larger than the sum of its proper divisors (34352967).

19821328453 is an equidigital number, since it uses as much as digits as its factorization.

19821328453 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34352966.

The product of its digits is 414720, while the sum is 46.

The spelling of 19821328453 in words is "nineteen billion, eight hundred twenty-one million, three hundred twenty-eight thousand, four hundred fifty-three".