669870 has 40 divisors (see below), whose sum is σ = 1803384. Its totient is φ = 178416.

The previous prime is 669869. The next prime is 669887. The reversal of 669870 is 78966.

669870 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 669870.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 397 + ... + 1223.

2⁶⁶⁹⁸⁷⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 669870, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (901692).

669870 is an abundant number, since it is smaller than the sum of its proper divisors (1133514).

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

669870 is a wasteful number, since it uses less digits than its factorization.

669870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 846 (or 837 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 669870 is about 818.4558631961. The cubic root of 669870 is about 87.4977414383.

The spelling of 669870 in words is "six hundred sixty-nine thousand, eight hundred seventy".