819297920 has 128 divisors (see below), whose sum is σ = 2291034240. Its totient is φ = 274305024.

The previous prime is 819297911. The next prime is 819297929. The reversal of 819297920 is 29792918.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (819297911) and next prime (819297929).

It is a tau number, because it is divible by the number of its divisors (128).

It is a Smith number, since the sum of its digits (47) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (819297929) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 190514 + ... + 194766.

It is an arithmetic number, because the mean of its divisors is an integer number (17898705).

Almost surely, 2^819297920 is an apocalyptic number.

819297920 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 819297920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1145517120).

819297920 is an abundant number, since it is smaller than the sum of its proper divisors (1471736320).

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

819297920 is a wasteful number, since it uses less digits than its factorization.

819297920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4322 (or 4310 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 47.

The square root of 819297920 is about 28623.3806528859. The cubic root of 819297920 is about 935.7229559690.

The spelling of 819297920 in words is "eight hundred nineteen million, two hundred ninety-seven thousand, nine hundred twenty".