665400960 has 256 divisors, whose sum is σ = 2693779200. Its totient is φ = 152064000.

The previous prime is 665400943. The next prime is 665400973. The reversal of 665400960 is 69004566.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

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 31 ways as a sum of consecutive naturals, for example, 118210 + ... + 123710.

It is an arithmetic number, because the mean of its divisors is an integer number (10522575).

Almost surely, 2^665400960 is an apocalyptic number.

665400960 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 665400960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1346889600).

665400960 is an abundant number, since it is smaller than the sum of its proper divisors (2028378240).

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

665400960 is a wasteful number, since it uses less digits than its factorization.

665400960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5536 (or 5518 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 36.

The square root of 665400960 is about 25795.3670258828. The cubic root of 665400960 is about 873.0272661859.

The spelling of 665400960 in words is "six hundred sixty-five million, four hundred thousand, nine hundred sixty".