669891289 has 4 divisors (see below), whose sum is σ = 679067956. Its totient is φ = 660714624.

The previous prime is 669891263. The next prime is 669891311. The reversal of 669891289 is 982198966.

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 233081289 + 436810000 = 15267^2 + 20900^2 .

It is a cyclic number.

It is not a de Polignac number, because 669891289 - 2⁷ = 669891161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (669891689) 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, 4588224 + ... + 4588369.

It is an arithmetic number, because the mean of its divisors is an integer number (169766989).

Almost surely, 2^669891289 is an apocalyptic number.

It is an amenable number.

669891289 is a deficient number, since it is larger than the sum of its proper divisors (9176667).

669891289 is an equidigital number, since it uses as much as digits as its factorization.

669891289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9176666.

The product of its digits is 3359232, while the sum is 58.

The square root of 669891289 is about 25882.2581897330. The cubic root of 669891289 is about 874.9866834436.

The spelling of 669891289 in words is "six hundred sixty-nine million, eight hundred ninety-one thousand, two hundred eighty-nine".