819409920 has 176 divisors, whose sum is σ = 2995628928. Its totient is φ = 187269120.

The previous prime is 819409919. The next prime is 819409931. The reversal of 819409920 is 29904918.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 103710 + ... + 111330.

Almost surely, 2^819409920 is an apocalyptic number.

819409920 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 819409920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1497814464).

819409920 is an abundant number, since it is smaller than the sum of its proper divisors (2176219008).

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

819409920 is a wasteful number, since it uses less digits than its factorization.

819409920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7656 (or 7638 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 42.

The square root of 819409920 is about 28625.3370285836. The cubic root of 819409920 is about 935.7655925538.

The spelling of 819409920 in words is "eight hundred nineteen million, four hundred nine thousand, nine hundred twenty".