669681805 has 16 divisors (see below), whose sum is σ = 868904064. Its totient is φ = 492552000.

The previous prime is 669681797. The next prime is 669681821. The reversal of 669681805 is 508186966.

669681805 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 669681805 - 2³ = 669681797 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 15 ways as a sum of consecutive naturals, for example, 4209 + ... + 36838.

It is an arithmetic number, because the mean of its divisors is an integer number (54306504).

Almost surely, 2^669681805 is an apocalyptic number.

669681805 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

669681805 is a deficient number, since it is larger than the sum of its proper divisors (199222259).

669681805 is a wasteful number, since it uses less digits than its factorization.

669681805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41316.

The product of its (nonzero) digits is 622080, while the sum is 49.

The square root of 669681805 is about 25878.2110084913. The cubic root of 669681805 is about 874.8954672403.

The spelling of 669681805 in words is "six hundred sixty-nine million, six hundred eighty-one thousand, eight hundred five".