6665512056 has 256 divisors, whose sum is σ = 21084364800. Its totient is φ = 1712088576.

The previous prime is 6665512019. The next prime is 6665512057. The reversal of 6665512056 is 6502155666.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 6665511999 and 6665512017.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6665512057) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 11966530 + ... + 11967086.

It is an arithmetic number, because the mean of its divisors is an integer number (82360800).

Almost surely, 2^6665512056 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6665512056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10542182400).

6665512056 is an abundant number, since it is smaller than the sum of its proper divisors (14418852744).

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

6665512056 is a wasteful number, since it uses less digits than its factorization.

6665512056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 778 (or 774 counting only the distinct ones).

The product of its (nonzero) digits is 324000, while the sum is 42.

The square root of 6665512056 is about 81642.5872691453. The cubic root of 6665512056 is about 1881.9633984652.

The spelling of 6665512056 in words is "six billion, six hundred sixty-five million, five hundred twelve thousand, fifty-six".