1664856 has 48 divisors (see below), whose sum is σ = 4750200. Its totient is φ = 525312.

The previous prime is 1664849. The next prime is 1664857. The reversal of 1664856 is 6584661.

1664856 is a `hidden beast` number, since 1 + 6 + 648 + 5 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 1664856.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664857) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 760 + ... + 1976.

2^1664856 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 1664856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2375100).

1664856 is an abundant number, since it is smaller than the sum of its proper divisors (3085344).

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

1664856 is a wasteful number, since it uses less digits than its factorization.

1664856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1248 (or 1241 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 1664856 is about 1290.2929899833. The cubic root of 1664856 is about 118.5201589376.

The spelling of 1664856 in words is "one million, six hundred sixty-four thousand, eight hundred fifty-six".