669929689 has 27 divisors (see below), whose sum is σ = 801799677. Its totient is φ = 559072800.

The previous prime is 669929669. The next prime is 669929707. The reversal of 669929689 is 986929966.

The square root of 669929689 is 25883.

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

It can be written as a sum of positive squares in 4 ways, for example, as 515971225 + 153958464 = 22715^2 + 12408^2 .

It is not a de Polignac number, because 669929689 - 2⁵ = 669929657 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 669929689.

It is not an unprimeable number, because it can be changed into a prime (669929629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 3701179 + ... + 3701359.

Almost surely, 2^669929689 is an apocalyptic number.

669929689 is the 25883-rd square number.

669929689 is the 12942-nd centered octagonal number.

It is an amenable number.

669929689 is a deficient number, since it is larger than the sum of its proper divisors (131869988).

669929689 is a wasteful number, since it uses less digits than its factorization.

669929689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 410 (or 205 counting only the distinct ones).

The product of its digits is 22674816, while the sum is 64.

The cubic root of 669929689 is about 875.0034020004.

Multiplying 669929689 by its sum of digits (64), we get a square (42875500096 = 207064²).

The spelling of 669929689 in words is "six hundred sixty-nine million, nine hundred twenty-nine thousand, six hundred eighty-nine".