669217255249 has 9 divisors (see below), whose sum is σ = 710913380241. Its totient is φ = 629838445440.

The previous prime is 669217255247. The next prime is 669217255313. The reversal of 669217255249 is 942552712966.

It is a happy number.

The square root of 669217255249 is 818057.

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 169130675025 + 500086580224 = 411255^2 + 707168^2 .

It is not a de Polignac number, because 669217255249 - 2¹ = 669217255247 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 669217255193 and 669217255202.

It is not an unprimeable number, because it can be changed into a prime (669217255241) 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, 13882909 + ... + 13931029.

Almost surely, 2^669217255249 is an apocalyptic number.

669217255249 is the 818057-th square number.

669217255249 is the 409029-th centered octagonal number.

It is an amenable number.

669217255249 is a deficient number, since it is larger than the sum of its proper divisors (41696124992).

669217255249 is an frugal number, since it uses more digits than its factorization.

669217255249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96276 (or 48138 counting only the distinct ones).

The product of its digits is 16329600, while the sum is 58.

The spelling of 669217255249 in words is "six hundred sixty-nine billion, two hundred seventeen million, two hundred fifty-five thousand, two hundred forty-nine".