813819664 has 80 divisors (see below), whose sum is σ = 1875737088. Its totient is φ = 334803456.

The previous prime is 813819653. The next prime is 813819689. The reversal of 813819664 is 466918318.

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, 277534 + ... + 280450.

Almost surely, 2^813819664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 813819664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (937868544).

813819664 is an abundant number, since it is smaller than the sum of its proper divisors (1061917424).

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

813819664 is a wasteful number, since it uses less digits than its factorization.

813819664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3032 (or 3026 counting only the distinct ones).

The product of its digits is 248832, while the sum is 46.

The square root of 813819664 is about 28527.5246735499. The cubic root of 813819664 is about 933.6327118968.

The spelling of 813819664 in words is "eight hundred thirteen million, eight hundred nineteen thousand, six hundred sixty-four".