666588969601 has 27 divisors (see below), whose sum is σ = 712454893731. Its totient is φ = 623584151424.

The previous prime is 666588969587. The next prime is 666588969679. The reversal of 666588969601 is 106969885666.

It is a happy number.

The square root of 666588969601 is 816449.

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

666588969601 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 299323881025 + 367265088576 = 547105^2 + 606024^2 .

It is not a de Polignac number, because 666588969601 - 2¹¹ = 666588967553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666588960601) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1504715286 + ... + 1504715728.

Almost surely, 2^666588969601 is an apocalyptic number.

666588969601 is the 816449-th square number.

666588969601 is the 408225-th centered octagonal number.

It is an amenable number.

666588969601 is a deficient number, since it is larger than the sum of its proper divisors (45865924130).

666588969601 is an frugal number, since it uses more digits than its factorization.

666588969601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1118 (or 559 counting only the distinct ones).

The product of its (nonzero) digits is 201553920, while the sum is 70.

The spelling of 666588969601 in words is "six hundred sixty-six billion, five hundred eighty-eight million, nine hundred sixty-nine thousand, six hundred one".