3640409 has 2 divisors, whose sum is σ = 3640410. Its totient is φ = 3640408.

The previous prime is 3640391. The next prime is 3640447. The reversal of 3640409 is 9040463.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2650384 + 990025 = 1628^2 + 995^2 .

It is an emirp because it is prime and its reverse (9040463) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3640409 is a prime.

It is a Chen prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (3640309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1820204 + 1820205.

It is an arithmetic number, because the mean of its divisors is an integer number (1820205).

Almost surely, 2^3640409 is an apocalyptic number.

It is an amenable number.

3640409 is a deficient number, since it is larger than the sum of its proper divisors (1).

3640409 is an equidigital number, since it uses as much as digits as its factorization.

3640409 is an evil number, because the sum of its binary digits is even.

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

The square root of 3640409 is about 1907.9855869477. The cubic root of 3640409 is about 153.8331948892.

The spelling of 3640409 in words is "three million, six hundred forty thousand, four hundred nine".