5661640 has 32 divisors (see below), whose sum is σ = 12960000. Its totient is φ = 2225344.

The previous prime is 5661637. The next prime is 5661647. The reversal of 5661640 is 461665.

It is a junction number, because it is equal to n+sod(n) for n = 5661599 and 5661608.

It is not an unprimeable number, because it can be changed into a prime (5661647) 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, 1161 + ... + 3559.

It is an arithmetic number, because the mean of its divisors is an integer number (405000).

Almost surely, 2^5661640 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 5661640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6480000).

5661640 is an abundant number, since it is smaller than the sum of its proper divisors (7298360).

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

5661640 is a wasteful number, since it uses less digits than its factorization.

5661640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2469 (or 2465 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 5661640 is about 2379.4200974187. The cubic root of 5661640 is about 178.2299766966.

The spelling of 5661640 in words is "five million, six hundred sixty-one thousand, six hundred forty".