1664256 has 72 divisors (see below), whose sum is σ = 4856544. Its totient is φ = 501760.

The previous prime is 1664251. The next prime is 1664261. The reversal of 1664256 is 6524661.

It is an interprime number because it is at equal distance from previous prime (1664251) and next prime (1664261).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8350 + ... + 8546.

It is an arithmetic number, because the mean of its divisors is an integer number (67452).

2^1664256 is an apocalyptic number.

1664256 is a gapful number since it is divisible by the number (16) 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 1664256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2428272).

1664256 is an abundant number, since it is smaller than the sum of its proper divisors (3192288).

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

1664256 is a wasteful number, since it uses less digits than its factorization.

1664256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 227 (or 213 counting only the distinct ones).

The product of its digits is 8640, while the sum is 30.

The square root of 1664256 is about 1290.0604636993. The cubic root of 1664256 is about 118.5059193397.

The spelling of 1664256 in words is "one million, six hundred sixty-four thousand, two hundred fifty-six".