3640661 has 2 divisors, whose sum is σ = 3640662. Its totient is φ = 3640660.

The previous prime is 3640649. The next prime is 3640697. The reversal of 3640661 is 1660463.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3010225 + 630436 = 1735^2 + 794^2 .

It is a cyclic number.

It is not a de Polignac number, because 3640661 - 2⁶ = 3640597 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 3640661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3640061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1820330 + 1820331.

It is an arithmetic number, because the mean of its divisors is an integer number (1820331).

Almost surely, 2^3640661 is an apocalyptic number.

It is an amenable number.

3640661 is a deficient number, since it is larger than the sum of its proper divisors (1).

3640661 is an equidigital number, since it uses as much as digits as its factorization.

3640661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 3640661 is about 1908.0516240396. The cubic root of 3640661 is about 153.8367444053.

The spelling of 3640661 in words is "three million, six hundred forty thousand, six hundred sixty-one".