1681656 has 32 divisors (see below), whose sum is σ = 4309200. Its totient is φ = 546560.

The previous prime is 1681651. The next prime is 1681661. The reversal of 1681656 is 6561861.

It is an interprime number because it is at equal distance from previous prime (1681651) and next prime (1681661).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1681651) 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 7 ways as a sum of consecutive naturals, for example, 130 + ... + 1838.

2^1681656 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 1681656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2154600).

1681656 is an abundant number, since it is smaller than the sum of its proper divisors (2627544).

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

1681656 is a wasteful number, since it uses less digits than its factorization.

1681656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1759 (or 1755 counting only the distinct ones).

The product of its digits is 8640, while the sum is 33.

The square root of 1681656 is about 1296.7867982055. The cubic root of 1681656 is about 118.9174862868.

The spelling of 1681656 in words is "one million, six hundred eighty-one thousand, six hundred fifty-six".