664465680 has 300 divisors, whose sum is σ = 2404225956. Its totient is φ = 170035200.

The previous prime is 664465657. The next prime is 664465691. The reversal of 664465680 is 86564466.

It can be written as a sum of positive squares in 6 ways, for example, as 431475984 + 232989696 = 20772^2 + 15264^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 10892850 + ... + 10892910.

Almost surely, 2^664465680 is an apocalyptic number.

664465680 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 664465680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1202112978).

664465680 is an abundant number, since it is smaller than the sum of its proper divisors (1739760276).

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

664465680 is a wasteful number, since it uses less digits than its factorization.

664465680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168 (or 112 counting only the distinct ones).

The product of its (nonzero) digits is 829440, while the sum is 45.

The square root of 664465680 is about 25777.2318141417. The cubic root of 664465680 is about 872.6180353332.

The spelling of 664465680 in words is "six hundred sixty-four million, four hundred sixty-five thousand, six hundred eighty".