66888959641 has 9 divisors (see below), whose sum is σ = 77811712149. Its totient is φ = 57331842204.

The previous prime is 66888959639. The next prime is 66888959647. The reversal of 66888959641 is 14695988866.

The square root of 66888959641 is 258629.

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

66888959641 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 66888959641 - 2¹ = 66888959639 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66888959647) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1791930 + ... + 1828876.

Almost surely, 2^66888959641 is an apocalyptic number.

66888959641 is the 258629-th square number.

66888959641 is the 129315-th centered octagonal number.

It is an amenable number.

66888959641 is a deficient number, since it is larger than the sum of its proper divisors (10922752508).

66888959641 is an frugal number, since it uses more digits than its factorization.

66888959641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73908 (or 36954 counting only the distinct ones).

The product of its digits is 179159040, while the sum is 70.

The spelling of 66888959641 in words is "sixty-six billion, eight hundred eighty-eight million, nine hundred fifty-nine thousand, six hundred forty-one".