5681664 has 100 divisors (see below), whose sum is σ = 17082054. Its totient is φ = 1880064.

The previous prime is 5681647. The next prime is 5681693. The reversal of 5681664 is 4661865.

It can be written as a sum of positive squares in only one way, i.e., 4665600 + 1016064 = 2160^2 + 1008^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 41404 + ... + 41540.

Almost surely, 2^5681664 is an apocalyptic number.

5681664 is a gapful number since it is divisible by the number (54) 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 5681664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8541027).

5681664 is an abundant number, since it is smaller than the sum of its proper divisors (11400390).

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

5681664 is an equidigital number, since it uses as much as digits as its factorization.

5681664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167 (or 142 counting only the distinct ones).

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

The square root of 5681664 is about 2383.6241314435. The cubic root of 5681664 is about 178.4398497988.

The spelling of 5681664 in words is "five million, six hundred eighty-one thousand, six hundred sixty-four".