1666240 has 56 divisors (see below), whose sum is σ = 4096512. Its totient is φ = 645120.

The previous prime is 1666237. The next prime is 1666261. The reversal of 1666240 is 426661.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13057 + ... + 13183.

It is an arithmetic number, because the mean of its divisors is an integer number (73152).

2^1666240 is an apocalyptic number.

1666240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1666240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2048256).

1666240 is an abundant number, since it is smaller than the sum of its proper divisors (2430272).

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

1666240 is a wasteful number, since it uses less digits than its factorization.

1666240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 185 (or 175 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 1666240 is about 1290.8291908692. The cubic root of 1666240 is about 118.5529919008.

The spelling of 1666240 in words is "one million, six hundred sixty-six thousand, two hundred forty".