669690 has 48 divisors (see below), whose sum is σ = 1991808. Its totient is φ = 152928.

The previous prime is 669689. The next prime is 669701. The reversal of 669690 is 96966.

It is a super-2 number, since 2×669690² = 896969392200, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 99 + ... + 1161.

It is an arithmetic number, because the mean of its divisors is an integer number (41496).

2⁶⁶⁹⁶⁹⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 669690, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (995904).

669690 is an abundant number, since it is smaller than the sum of its proper divisors (1322118).

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

669690 is a wasteful number, since it uses less digits than its factorization.

669690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1083 (or 1080 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 36.

The square root of 669690 is about 818.3458926395. The cubic root of 669690 is about 87.4899035970.

It can be divided in two parts, 6696 and 90, that added together give a triangular number (6786 = T₁₁₆).

The spelling of 669690 in words is "six hundred sixty-nine thousand, six hundred ninety".