1669986 has 36 divisors (see below), whose sum is σ = 3833622. Its totient is φ = 525312.

The previous prime is 1669979. The next prime is 1669999. The reversal of 1669986 is 6899661.

It can be written as a sum of positive squares in only one way, i.e., 938961 + 731025 = 969^2 + 855^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 6370 + ... + 6626.

2^1669986 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1669986, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1916811).

1669986 is an abundant number, since it is smaller than the sum of its proper divisors (2163636).

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

1669986 is a wasteful number, since it uses less digits than its factorization.

1669986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 303 (or 281 counting only the distinct ones).

The product of its digits is 139968, while the sum is 45.

The square root of 1669986 is about 1292.2793815580. The cubic root of 1669986 is about 118.6417680511.

The spelling of 1669986 in words is "one million, six hundred sixty-nine thousand, nine hundred eighty-six".