684623856400 has 135 divisors (see below), whose sum is σ = 1808411182879. Its totient is φ = 248887936000.

The previous prime is 684623856359. The next prime is 684623856473. The reversal of 684623856400 is 4658326486.

The square root of 684623856400 is 827420.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 26033177104 + 658590679296 = 161348^2 + 811536^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 182030520 + ... + 182034280.

Almost surely, 2^684623856400 is an apocalyptic number.

684623856400 is the 827420-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 684623856400

684623856400 is an abundant number, since it is smaller than the sum of its proper divisors (1123787326479).

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

684623856400 is an equidigital number, since it uses as much as digits as its factorization.

684623856400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7562 (or 3779 counting only the distinct ones).

The product of its (nonzero) digits is 6635520, while the sum is 52.

The spelling of 684623856400 in words is "six hundred eighty-four billion, six hundred twenty-three million, eight hundred fifty-six thousand, four hundred".