665432409600 has 1920 divisors, whose sum is σ = 3039576883200. Its totient is φ = 139146854400.

The previous prime is 665432409541. The next prime is 665432409613. The reversal of 665432409600 is 6904234566.

665432409600 is a `hidden beast` number, since 6 + 6 + 5 + 4 + 32 + 4 + 0 + 9 + 600 = 666.

It is a tau number, because it is divible by the number of its divisors (1920).

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 (19) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 1424908567 + ... + 1424909033.

It is an arithmetic number, because the mean of its divisors is an integer number (1583112960).

Almost surely, 2^665432409600 is an apocalyptic number.

665432409600 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 665432409600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1519788441600).

665432409600 is an abundant number, since it is smaller than the sum of its proper divisors (2374144473600).

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

665432409600 is a wasteful number, since it uses less digits than its factorization.

665432409600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 561 (or 534 counting only the distinct ones).

The product of its (nonzero) digits is 933120, while the sum is 45.

The spelling of 665432409600 in words is "six hundred sixty-five billion, four hundred thirty-two million, four hundred nine thousand, six hundred".