665540195798016 has 880 divisors, whose sum is σ = 2500998660940032. Its totient is φ = 171251822592000.

The previous prime is 665540195797979. The next prime is 665540195798041. The reversal of 665540195798016 is 610897591045566.

665540195798016 is a `hidden beast` number, since 6 + 6 + 5 + 5 + 40 + 1 + 9 + 579 + 8 + 0 + 1 + 6 = 666.

It is a super-3 number, since 3×665540195798016³ (a number of 45 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 682888666 + ... + 683862566.

Almost surely, 2^{665540195798016} is an apocalyptic number.

665540195798016 is a gapful number since it is divisible by the number (66) 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 665540195798016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1250499330470016).

665540195798016 is an abundant number, since it is smaller than the sum of its proper divisors (1835458465142016).

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

665540195798016 is a wasteful number, since it uses less digits than its factorization.

665540195798016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 974058 (or 974031 counting only the distinct ones).

The product of its (nonzero) digits is 489888000, while the sum is 72.

The spelling of 665540195798016 in words is "six hundred sixty-five trillion, five hundred forty billion, one hundred ninety-five million, seven hundred ninety-eight thousand, sixteen".