5621661 has 12 divisors (see below), whose sum is σ = 8140860. Its totient is φ = 3738240.

The previous prime is 5621653. The next prime is 5621687. The reversal of 5621661 is 1661265.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 864900 + 4756761 = 930^2 + 2181^2 .

It is not a de Polignac number, because 5621661 - 2³ = 5621653 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5628661) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5941 + ... + 6821.

It is an arithmetic number, because the mean of its divisors is an integer number (678405).

Almost surely, 2^5621661 is an apocalyptic number.

It is an amenable number.

5621661 is a deficient number, since it is larger than the sum of its proper divisors (2519199).

5621661 is a wasteful number, since it uses less digits than its factorization.

5621661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1596 (or 1593 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 5621661 is about 2371.0042176259. The cubic root of 5621661 is about 177.8094687283.

The spelling of 5621661 in words is "five million, six hundred twenty-one thousand, six hundred sixty-one".