39908609 has 4 divisors (see below), whose sum is σ = 42978516. Its totient is φ = 36838704.

The previous prime is 39908597. The next prime is 39908633. The reversal of 39908609 is 90680993.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90680993 = 13 ⋅6975461.

It can be written as a sum of positive squares in 2 ways, for example, as 2356225 + 37552384 = 1535^2 + 6128^2 .

It is a cyclic number.

It is not a de Polignac number, because 39908609 - 2²⁴ = 23131393 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 39908609.

It is not an unprimeable number, because it can be changed into a prime (39908699) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1534934 + ... + 1534959.

It is an arithmetic number, because the mean of its divisors is an integer number (10744629).

Almost surely, 2^39908609 is an apocalyptic number.

It is an amenable number.

39908609 is a deficient number, since it is larger than the sum of its proper divisors (3069907).

39908609 is a wasteful number, since it uses less digits than its factorization.

39908609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3069906.

The product of its (nonzero) digits is 104976, while the sum is 44.

The square root of 39908609 is about 6317.3260957465. The cubic root of 39908609 is about 341.7345300322.

The spelling of 39908609 in words is "thirty-nine million, nine hundred eight thousand, six hundred nine".