818705664 has 144 divisors (see below), whose sum is σ = 2767085440. Its totient is φ = 233902080.

The previous prime is 818705659. The next prime is 818705683. The reversal of 818705664 is 466507818.

It is a happy number.

818705664 is a `hidden beast` number, since 8 + 1 + 87 + 0 + 566 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

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, 39924 + ... + 56844.

Almost surely, 2^818705664 is an apocalyptic number.

818705664 is a gapful number since it is divisible by the number (84) 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 818705664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1383542720).

818705664 is an abundant number, since it is smaller than the sum of its proper divisors (1948379776).

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

818705664 is a wasteful number, since it uses less digits than its factorization.

818705664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16953 (or 16933 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 45.

The square root of 818705664 is about 28613.0331142995. The cubic root of 818705664 is about 935.4974290828.

The spelling of 818705664 in words is "eight hundred eighteen million, seven hundred five thousand, six hundred sixty-four".