819205920 has 384 divisors, whose sum is σ = 3200601600. Its totient is φ = 194310144.

The previous prime is 819205913. The next prime is 819205921. The reversal of 819205920 is 29502918.

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

It is not an unprimeable number, because it can be changed into a prime (819205921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1628389 + ... + 1628891.

It is an arithmetic number, because the mean of its divisors is an integer number (8334900).

Almost surely, 2^819205920 is an apocalyptic number.

819205920 is a gapful number since it is divisible by the number (80) 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 819205920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1600300800).

819205920 is an abundant number, since it is smaller than the sum of its proper divisors (2381395680).

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

819205920 is a wasteful number, since it uses less digits than its factorization.

819205920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 569 (or 555 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The square root of 819205920 is about 28621.7735299544. The cubic root of 819205920 is about 935.6879301530.

The spelling of 819205920 in words is "eight hundred nineteen million, two hundred five thousand, nine hundred twenty".