39949909 has 2 divisors, whose sum is σ = 39949910. Its totient is φ = 39949908.

The previous prime is 39949901. The next prime is 39949927. The reversal of 39949909 is 90994993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 38167684 + 1782225 = 6178^2 + 1335^2 .

It is a cyclic number.

It is not a de Polignac number, because 39949909 - 2³ = 39949901 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39949901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19974954 + 19974955.

It is an arithmetic number, because the mean of its divisors is an integer number (19974955).

Almost surely, 2^39949909 is an apocalyptic number.

It is an amenable number.

39949909 is a deficient number, since it is larger than the sum of its proper divisors (1).

39949909 is an equidigital number, since it uses as much as digits as its factorization.

39949909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 708588, while the sum is 52.

The square root of 39949909 is about 6320.5940385378. The cubic root of 39949909 is about 341.8523723615.

The spelling of 39949909 in words is "thirty-nine million, nine hundred forty-nine thousand, nine hundred nine".