5661000 has 192 divisors, whose sum is σ = 20807280. Its totient is φ = 1382400.

The previous prime is 5660999. The next prime is 5661001. The reversal of 5661000 is 1665.

5661000 is a `hidden beast` number, since 5 + 661 + 0 + 0 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (5660999) and next prime (5661001).

It can be written as a sum of positive squares in 8 ways, for example, as 1572516 + 4088484 = 1254^2 + 2022^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5661001) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 152982 + ... + 153018.

Almost surely, 2^5661000 is an apocalyptic number.

5661000 is a gapful number since it is divisible by the number (50) 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 5661000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10403640).

5661000 is an abundant number, since it is smaller than the sum of its proper divisors (15146280).

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

5661000 is a wasteful number, since it uses less digits than its factorization.

5661000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81 (or 64 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 5661000 is about 2379.2856070678. The cubic root of 5661000 is about 178.2232606518.

Adding to 5661000 its reverse (1665), we get a palindrome (5662665).

The spelling of 5661000 in words is "five million, six hundred sixty-one thousand".