3556661 has 6 divisors (see below), whose sum is σ = 3676086. Its totient is φ = 3441000.

The previous prime is 3556649. The next prime is 3556669. The reversal of 3556661 is 1666553.

3556661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 2907025 + 649636 = 1705^2 + 806^2 .

It is a de Polignac number, because none of the positive numbers 2^k-3556661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3556669) 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 5 ways as a sum of consecutive naturals, for example, 890 + ... + 2811.

It is an arithmetic number, because the mean of its divisors is an integer number (612681).

Almost surely, 2^3556661 is an apocalyptic number.

3556661 is a gapful number since it is divisible by the number (31) formed by its first and last digit.

It is an amenable number.

3556661 is a deficient number, since it is larger than the sum of its proper divisors (119425).

3556661 is an equidigital number, since it uses as much as digits as its factorization.

3556661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3763 (or 3732 counting only the distinct ones).

The product of its digits is 16200, while the sum is 32.

The square root of 3556661 is about 1885.9111856076. The cubic root of 3556661 is about 152.6443817598.

The spelling of 3556661 in words is "three million, five hundred fifty-six thousand, six hundred sixty-one".