665944855009800 has 48 divisors (see below), whose sum is σ = 2064429050532240. Its totient is φ = 177585294669120.

The previous prime is 665944855009793. The next prime is 665944855009801. The reversal of 665944855009800 is 8900558449566.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (665944855009801) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 554954045242 + ... + 554954046441.

It is an arithmetic number, because the mean of its divisors is an integer number (43008938552755).

Almost surely, 2^{665944855009800} is an apocalyptic number.

665944855009800 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

665944855009800 is an abundant number, since it is smaller than the sum of its proper divisors (1398484195522440).

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

665944855009800 is a wasteful number, since it uses less digits than its factorization.

665944855009800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1109908091702 (or 1109908091693 counting only the distinct ones).

The product of its (nonzero) digits is 373248000, while the sum is 69.

The spelling of 665944855009800 in words is "six hundred sixty-five trillion, nine hundred forty-four billion, eight hundred fifty-five million, nine thousand, eight hundred".