665942999040 has 960 divisors, whose sum is σ = 2618172426240. Its totient is φ = 159252480000.

The previous prime is 665942998993. The next prime is 665942999123. The reversal of 665942999040 is 40999249566.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2457354105 + ... + 2457354375.

It is an arithmetic number, because the mean of its divisors is an integer number (2727262944).

Almost surely, 2^665942999040 is an apocalyptic number.

665942999040 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 665942999040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1309086213120).

665942999040 is an abundant number, since it is smaller than the sum of its proper divisors (1952229427200).

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

665942999040 is a wasteful number, since it uses less digits than its factorization.

665942999040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 425 (or 393 counting only the distinct ones).

The product of its (nonzero) digits is 37791360, while the sum is 63.

The spelling of 665942999040 in words is "six hundred sixty-five billion, nine hundred forty-two million, nine hundred ninety-nine thousand, forty".