665040439870884 has 243 divisors, whose sum is σ = 2149511500551051. Its totient is φ = 172734681984480.

The previous prime is 665040439870879. The next prime is 665040439870951. The reversal of 665040439870884 is 488078934040566.

The square root of 665040439870884 is 25788378.

It is a perfect power (a square), and thus also a powerful number.

665040439870884 is a `hidden beast` number, since 6 + 6 + 5 + 0 + 40 + 439 + 8 + 70 + 8 + 84 = 666.

It is a super-2 number, since 2×665040439870884² (a number of 30 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 11914202727 + ... + 11914258545.

Almost surely, 2^{665040439870884} is an apocalyptic number.

665040439870884 is the 25788378-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 665040439870884

665040439870884 is an abundant number, since it is smaller than the sum of its proper divisors (1484471060680167).

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

665040439870884 is an equidigital number, since it uses as much as digits as its factorization.

665040439870884 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111684 (or 55842 counting only the distinct ones).

The product of its (nonzero) digits is 1114767360, while the sum is 72.

The spelling of 665040439870884 in words is "six hundred sixty-five trillion, forty billion, four hundred thirty-nine million, eight hundred seventy thousand, eight hundred eighty-four".