819928421 has 8 divisors (see below), whose sum is σ = 883335264. Its totient is φ = 756569520.

The previous prime is 819928321. The next prime is 819928427. The reversal of 819928421 is 124829918.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-819928421 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 (819928427) 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 7 ways as a sum of consecutive naturals, for example, 28670 + ... + 49616.

It is an arithmetic number, because the mean of its divisors is an integer number (110416908).

Almost surely, 2^819928421 is an apocalyptic number.

It is an amenable number.

819928421 is a deficient number, since it is larger than the sum of its proper divisors (63406843).

819928421 is a wasteful number, since it uses less digits than its factorization.

819928421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23971.

The product of its digits is 82944, while the sum is 44.

The square root of 819928421 is about 28634.3922757233. The cubic root of 819928421 is about 935.9629268713.

The spelling of 819928421 in words is "eight hundred nineteen million, nine hundred twenty-eight thousand, four hundred twenty-one".