1668656 has 40 divisors (see below), whose sum is σ = 3720000. Its totient is φ = 717120.

The previous prime is 1668649. The next prime is 1668679. The reversal of 1668656 is 6568661.

It is a Harshad number since it is a multiple of its sum of digits (38).

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, 3095 + ... + 3593.

It is an arithmetic number, because the mean of its divisors is an integer number (93000).

2^1668656 is an apocalyptic number.

1668656 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 1668656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1860000).

1668656 is an abundant number, since it is smaller than the sum of its proper divisors (2051344).

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

1668656 is a wasteful number, since it uses less digits than its factorization.

1668656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 537 (or 531 counting only the distinct ones).

The product of its digits is 51840, while the sum is 38.

The square root of 1668656 is about 1291.7646844530. The cubic root of 1668656 is about 118.6102637032.

The spelling of 1668656 in words is "one million, six hundred sixty-eight thousand, six hundred fifty-six".