669205161 has 9 divisors (see below), whose sum is σ = 966741789. Its totient is φ = 446085036.

The previous prime is 669205109. The next prime is 669205193. The reversal of 669205161 is 161502966.

The square root of 669205161 is 25869.

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

669205161 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 (9).

It is not a de Polignac number, because 669205161 - 2²¹ = 667108009 is a prime.

It is not an unprimeable number, because it can be changed into a prime (669285161) 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, 73296 + ... + 81918.

Almost surely, 2^669205161 is an apocalyptic number.

669205161 is the 25869-th square number.

669205161 is the 12935-th centered octagonal number.

It is an amenable number.

669205161 is a deficient number, since it is larger than the sum of its proper divisors (297536628).

669205161 is an frugal number, since it uses more digits than its factorization.

669205161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17252 (or 8626 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The cubic root of 669205161 is about 874.6878499076.

Multiplying 669205161 by its sum of digits (36), we get a square (24091385796 = 155214²).

The spelling of 669205161 in words is "six hundred sixty-nine million, two hundred five thousand, one hundred sixty-one".