664418880 has 168 divisors, whose sum is σ = 2296250424. Its totient is φ = 176332800.

The previous prime is 664418873. The next prime is 664418897. The reversal of 664418880 is 88814466.

It can be written as a sum of positive squares in 4 ways, for example, as 55711296 + 608707584 = 7464^2 + 24672^2 .

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

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 23 ways as a sum of consecutive naturals, for example, 808870 + ... + 809690.

Almost surely, 2^664418880 is an apocalyptic number.

664418880 is a gapful number since it is divisible by the number (60) 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 664418880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1148125212).

664418880 is an abundant number, since it is smaller than the sum of its proper divisors (1631831544).

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

664418880 is a wasteful number, since it uses less digits than its factorization.

664418880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1125 (or 1112 counting only the distinct ones).

The product of its (nonzero) digits is 294912, while the sum is 45.

The square root of 664418880 is about 25776.3240203098. The cubic root of 664418880 is about 872.5975479531.

The spelling of 664418880 in words is "six hundred sixty-four million, four hundred eighteen thousand, eight hundred eighty".