820686368 has 36 divisors (see below), whose sum is σ = 1689064398. Its totient is φ = 392494080.

The previous prime is 820686337. The next prime is 820686379. The reversal of 820686368 is 863686028.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 443860624 + 376825744 = 21068^2 + 19412^2 .

It is a super-2 number, since 2×820686368² = 1347052229242062848, which contains 22 as substring.

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 5 ways as a sum of consecutive naturals, for example, 7313 + ... + 41168.

Almost surely, 2^820686368 is an apocalyptic number.

It is an amenable number.

820686368 is an abundant number, since it is smaller than the sum of its proper divisors (868378030).

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

820686368 is a wasteful number, since it uses less digits than its factorization.

820686368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48537 (or 48506 counting only the distinct ones).

The product of its (nonzero) digits is 663552, while the sum is 47.

The square root of 820686368 is about 28647.6241248729. The cubic root of 820686368 is about 936.2512413925.

The spelling of 820686368 in words is "eight hundred twenty million, six hundred eighty-six thousand, three hundred sixty-eight".