666777696 has 96 divisors (see below), whose sum is σ = 1909071360. Its totient is φ = 202535424.

The previous prime is 666777691. The next prime is 666777707. The reversal of 666777696 is 696777666.

666777696 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-3 number, since 3×666777696³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666777691) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 95211 + ... + 101973.

It is an arithmetic number, because the mean of its divisors is an integer number (19886160).

Almost surely, 2^666777696 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 666777696, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (954535680).

666777696 is an abundant number, since it is smaller than the sum of its proper divisors (1242293664).

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

666777696 is a wasteful number, since it uses less digits than its factorization.

666777696 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6868 (or 6860 counting only the distinct ones).

The product of its digits is 24004512, while the sum is 60.

The square root of 666777696 is about 25822.0389589978. The cubic root of 666777696 is about 873.6289585726.

The spelling of 666777696 in words is "six hundred sixty-six million, seven hundred seventy-seven thousand, six hundred ninety-six".