1819409920 has 80 divisors (see below), whose sum is σ = 4394562480. Its totient is φ = 722386944.

The previous prime is 1819409881. The next prime is 1819409929. The reversal of 1819409920 is 299049181.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1819409929) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 353284 + ... + 358396.

It is an arithmetic number, because the mean of its divisors is an integer number (54932031).

Almost surely, 2^1819409920 is an apocalyptic number.

1819409920 is a gapful number since it is divisible by the number (10) 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 1819409920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2197281240).

1819409920 is an abundant number, since it is smaller than the sum of its proper divisors (2575152560).

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

1819409920 is an equidigital number, since it uses as much as digits as its factorization.

1819409920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5275 (or 5259 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 43.

The square root of 1819409920 is about 42654.5416104780. The cubic root of 1819409920 is about 1220.7971856904.

The spelling of 1819409920 in words is "one billion, eight hundred nineteen million, four hundred nine thousand, nine hundred twenty".