66766425664 has 21 divisors (see below), whose sum is σ = 132493728027. Its totient is φ = 33382179264.

The previous prime is 66766425659. The next prime is 66766425673. The reversal of 66766425664 is 46652466766.

It is a happy number.

The square root of 66766425664 is 258392.

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

66766425664 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66766425599 and 66766425608.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 2050987 + ... + 2083285.

Almost surely, 2^66766425664 is an apocalyptic number.

66766425664 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

66766425664 is the 258392-nd square number.

It is an amenable number.

66766425664 is a deficient number, since it is larger than the sum of its proper divisors (65727302363).

66766425664 is an frugal number, since it uses more digits than its factorization.

66766425664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64610 (or 32301 counting only the distinct ones).

The product of its digits is 52254720, while the sum is 58.

The spelling of 66766425664 in words is "sixty-six billion, seven hundred sixty-six million, four hundred twenty-five thousand, six hundred sixty-four".