665209480320 has 2560 divisors, whose sum is σ = 3199046400000. Its totient is φ = 130218762240.

The previous prime is 665209480283. The next prime is 665209480357. The reversal of 665209480320 is 23084902566.

665209480320 is a `hidden beast` number, since 6 + 6 + 520 + 94 + 8 + 0 + 32 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (665209480283) and next prime (665209480357).

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 319 ways as a sum of consecutive naturals, for example, 3716253991 + ... + 3716254169.

It is an arithmetic number, because the mean of its divisors is an integer number (1249627500).

Almost surely, 2^665209480320 is an apocalyptic number.

665209480320 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 665209480320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1599523200000).

665209480320 is an abundant number, since it is smaller than the sum of its proper divisors (2533836919680).

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

665209480320 is a wasteful number, since it uses less digits than its factorization.

665209480320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261 (or 226 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 45.

The spelling of 665209480320 in words is "six hundred sixty-five billion, two hundred nine million, four hundred eighty thousand, three hundred twenty".