665477382721536 has 2912 divisors, whose sum is σ = 2605073545297920. Its totient is φ = 164854982246400.

The previous prime is 665477382721451. The next prime is 665477382721603. The reversal of 665477382721536 is 635127283774566.

665477382721536 is a `hidden beast` number, since 6 + 6 + 5 + 4 + 7 + 7 + 3 + 82 + 7 + 2 + 1 + 536 = 666.

It is a super-2 number, since 2×665477382721536² (a number of 30 digits) contains 22 as substring.

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

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 223 ways as a sum of consecutive naturals, for example, 520310697345 + ... + 520310698623.

Almost surely, 2^{665477382721536} is an apocalyptic number.

665477382721536 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 665477382721536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1302536772648960).

665477382721536 is an abundant number, since it is smaller than the sum of its proper divisors (1939596162576384).

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

665477382721536 is a wasteful number, since it uses less digits than its factorization.

665477382721536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1443 (or 1406 counting only the distinct ones).

The product of its digits is 2133734400, while the sum is 72.

The spelling of 665477382721536 in words is "six hundred sixty-five trillion, four hundred seventy-seven billion, three hundred eighty-two million, seven hundred twenty-one thousand, five hundred thirty-six".