669870816 has 144 divisors (see below), whose sum is σ = 1864758672. Its totient is φ = 210462720.

The previous prime is 669870811. The next prime is 669870823. The reversal of 669870816 is 618078966.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669870811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4889500 + ... + 4889636.

It is an arithmetic number, because the mean of its divisors is an integer number (12949713).

Almost surely, 2^669870816 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 669870816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (932379336).

669870816 is an abundant number, since it is smaller than the sum of its proper divisors (1194887856).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

669870816 is a wasteful number, since it uses less digits than its factorization.

669870816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 265 (or 226 counting only the distinct ones).

The product of its (nonzero) digits is 870912, while the sum is 51.

The square root of 669870816 is about 25881.8626841269. The cubic root of 669870816 is about 874.9777696665.

The spelling of 669870816 in words is "six hundred sixty-nine million, eight hundred seventy thousand, eight hundred sixteen".