39945609 has 24 divisors (see below), whose sum is σ = 65052960. Its totient is φ = 24207480.

The previous prime is 39945593. The next prime is 39945617. The reversal of 39945609 is 90654993.

It is a happy number.

39945609 is a `hidden beast` number, since 39 + 9 + 4 + 5 + 609 = 666.

It is not a de Polignac number, because 39945609 - 2⁴ = 39945593 is a prime.

It is not an unprimeable number, because it can be changed into a prime (39945649) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2847 + ... + 9380.

It is an arithmetic number, because the mean of its divisors is an integer number (2710540).

Almost surely, 2^39945609 is an apocalyptic number.

It is an amenable number.

39945609 is a deficient number, since it is larger than the sum of its proper divisors (25107351).

39945609 is a wasteful number, since it uses less digits than its factorization.

39945609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12258 (or 12241 counting only the distinct ones).

The product of its (nonzero) digits is 262440, while the sum is 45.

The square root of 39945609 is about 6320.2538714833. The cubic root of 39945609 is about 341.8401068521.

The spelling of 39945609 in words is "thirty-nine million, nine hundred forty-five thousand, six hundred nine".