1820639804 has 12 divisors (see below), whose sum is σ = 3195576384. Its totient is φ = 907617984.

The previous prime is 1820639771. The next prime is 1820639813. The reversal of 1820639804 is 4089360281.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 673964 + ... + 676659.

It is an arithmetic number, because the mean of its divisors is an integer number (266298032).

Almost surely, 2^1820639804 is an apocalyptic number.

It is an amenable number.

1820639804 is a deficient number, since it is larger than the sum of its proper divisors (1374936580).

1820639804 is a wasteful number, since it uses less digits than its factorization.

1820639804 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1350964 (or 1350962 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 41.

The square root of 1820639804 is about 42668.9559750412. The cubic root of 1820639804 is about 1221.0722017313.

The spelling of 1820639804 in words is "one billion, eight hundred twenty million, six hundred thirty-nine thousand, eight hundred four".