3688661 has 2 divisors, whose sum is σ = 3688662. Its totient is φ = 3688660.

The previous prime is 3688649. The next prime is 3688667. The reversal of 3688661 is 1668863.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2869636 + 819025 = 1694^2 + 905^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3688661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3688667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1844330 + 1844331.

It is an arithmetic number, because the mean of its divisors is an integer number (1844331).

Almost surely, 2^3688661 is an apocalyptic number.

It is an amenable number.

3688661 is a deficient number, since it is larger than the sum of its proper divisors (1).

3688661 is an equidigital number, since it uses as much as digits as its factorization.

3688661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 41472, while the sum is 38.

The square root of 3688661 is about 1920.5887118277. The cubic root of 3688661 is about 154.5098774245.

The spelling of 3688661 in words is "three million, six hundred eighty-eight thousand, six hundred sixty-one".