819802120 has 48 divisors (see below), whose sum is σ = 1946780460. Its totient is φ = 310656384.

The previous prime is 819802117. The next prime is 819802121. The reversal of 819802120 is 21208918.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 788598724 + 31203396 = 28082^2 + 5586^2 .

It is not an unprimeable number, because it can be changed into a prime (819802121) 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 11 ways as a sum of consecutive naturals, for example, 13947 + ... + 42826.

Almost surely, 2^819802120 is an apocalyptic number.

It is an amenable number.

819802120 is an abundant number, since it is smaller than the sum of its proper divisors (1126978340).

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

819802120 is a wasteful number, since it uses less digits than its factorization.

819802120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56822 (or 56799 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 31.

The square root of 819802120 is about 28632.1867834086. The cubic root of 819802120 is about 935.9148661215.

It can be divided in two parts, 81980 and 2120, that added together give a square (84100 = 290²).

The spelling of 819802120 in words is "eight hundred nineteen million, eight hundred two thousand, one hundred twenty".