669659871 has 4 divisors (see below), whose sum is σ = 892879832. Its totient is φ = 446439912.

The previous prime is 669659843. The next prime is 669659873. The reversal of 669659871 is 178956966.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 669659871 - 2¹¹ = 669657823 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669659873) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 111609976 + ... + 111609981.

It is an arithmetic number, because the mean of its divisors is an integer number (223219958).

Almost surely, 2^669659871 is an apocalyptic number.

669659871 is a deficient number, since it is larger than the sum of its proper divisors (223219961).

669659871 is a wasteful number, since it uses less digits than its factorization.

669659871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223219960.

The product of its digits is 4898880, while the sum is 57.

The square root of 669659871 is about 25877.7872122019. The cubic root of 669659871 is about 874.8859153573.

The spelling of 669659871 in words is "six hundred sixty-nine million, six hundred fifty-nine thousand, eight hundred seventy-one".