664395540480 has 960 divisors, whose sum is σ = 2788978832640. Its totient is φ = 148104806400.

The previous prime is 664395540461. The next prime is 664395540491. The reversal of 664395540480 is 84045593466.

664395540480 is a `hidden beast` number, since 6 + 6 + 4 + 3 + 9 + 554 + 0 + 4 + 80 = 666.

It is a tau number, because it is divible by the number of its divisors (960).

It is a super-2 number, since 2×664395540480² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 238047885 + ... + 238050675.

It is an arithmetic number, because the mean of its divisors is an integer number (2905186284).

Almost surely, 2^664395540480 is an apocalyptic number.

664395540480 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 664395540480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1394489416320).

664395540480 is an abundant number, since it is smaller than the sum of its proper divisors (2124583292160).

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

664395540480 is a wasteful number, since it uses less digits than its factorization.

664395540480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2878 (or 2849 counting only the distinct ones).

The product of its (nonzero) digits is 12441600, while the sum is 54.

The spelling of 664395540480 in words is "six hundred sixty-four billion, three hundred ninety-five million, five hundred forty thousand, four hundred eighty".