669679221 has 8 divisors (see below), whose sum is σ = 909753120. Its totient is φ = 438029072.

The previous prime is 669679207. The next prime is 669679237. The reversal of 669679221 is 122976966.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 669679221 - 2⁵ = 669679189 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669679321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2105751 + ... + 2106068.

It is an arithmetic number, because the mean of its divisors is an integer number (113719140).

Almost surely, 2^669679221 is an apocalyptic number.

It is an amenable number.

669679221 is a deficient number, since it is larger than the sum of its proper divisors (240073899).

669679221 is a wasteful number, since it uses less digits than its factorization.

669679221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4211875.

The product of its digits is 489888, while the sum is 48.

The square root of 669679221 is about 25878.1610822717. The cubic root of 669679221 is about 874.8943419632.

The spelling of 669679221 in words is "six hundred sixty-nine million, six hundred seventy-nine thousand, two hundred twenty-one".