666522697 has 4 divisors (see below), whose sum is σ = 667563156. Its totient is φ = 665482240.

The previous prime is 666522671. The next prime is 666522709. The reversal of 666522697 is 796225666.

666522697 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 467035321 + 199487376 = 21611^2 + 14124^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-666522697 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 666522697.

It is not an unprimeable number, because it can be changed into a prime (666522667) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 519268 + ... + 520549.

It is an arithmetic number, because the mean of its divisors is an integer number (166890789).

Almost surely, 2^666522697 is an apocalyptic number.

It is an amenable number.

666522697 is a deficient number, since it is larger than the sum of its proper divisors (1040459).

666522697 is a wasteful number, since it uses less digits than its factorization.

666522697 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1040458.

The product of its digits is 1632960, while the sum is 49.

The square root of 666522697 is about 25817.1008635749. The cubic root of 666522697 is about 873.5175756649.

The spelling of 666522697 in words is "six hundred sixty-six million, five hundred twenty-two thousand, six hundred ninety-seven".