669808565 has 8 divisors (see below), whose sum is σ = 808702368. Its totient is φ = 532558800.

The previous prime is 669808543. The next prime is 669808583. The reversal of 669808565 is 565808966.

It is a happy number.

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

It is not a de Polignac number, because 669808565 - 2¹⁶ = 669743029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 410111 + ... + 411740.

It is an arithmetic number, because the mean of its divisors is an integer number (101087796).

Almost surely, 2^669808565 is an apocalyptic number.

It is an amenable number.

669808565 is a deficient number, since it is larger than the sum of its proper divisors (138893803).

669808565 is a wasteful number, since it uses less digits than its factorization.

669808565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 822019.

The product of its (nonzero) digits is 3110400, while the sum is 53.

The square root of 669808565 is about 25880.6600572706. The cubic root of 669808565 is about 874.9506649735.

The spelling of 669808565 in words is "six hundred sixty-nine million, eight hundred eight thousand, five hundred sixty-five".