664681478400 has 729 divisors, whose sum is σ = 2464122819249. Its totient is φ = 170934865920.

The previous prime is 664681478359. The next prime is 664681478413. The reversal of 664681478400 is 4874186466.

The square root of 664681478400 is 815280.

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

664681478400 is a `hidden beast` number, since 66 + 468 + 1 + 47 + 84 + 0 + 0 = 666.

It can be written as a sum of positive squares in only one way, i.e., 239285332224 + 425396146176 = 489168^2 + 652224^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 8413689561 + ... + 8413689639.

Almost surely, 2^664681478400 is an apocalyptic number.

664681478400 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

664681478400 is the 815280-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664681478400

664681478400 is an abundant number, since it is smaller than the sum of its proper divisors (1799441340849).

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

664681478400 is an equidigital number, since it uses as much as digits as its factorization.

664681478400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276 (or 132 counting only the distinct ones).

The product of its (nonzero) digits is 6193152, while the sum is 54.

The spelling of 664681478400 in words is "six hundred sixty-four billion, six hundred eighty-one million, four hundred seventy-eight thousand, four hundred".