39961609 has 4 divisors (see below), whose sum is σ = 40811904. Its totient is φ = 39111316.

The previous prime is 39961589. The next prime is 39961619. The reversal of 39961609 is 90616993.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 39961609 - 2¹¹ = 39959561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (39961619) 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, 425077 + ... + 425170.

It is an arithmetic number, because the mean of its divisors is an integer number (10202976).

Almost surely, 2^39961609 is an apocalyptic number.

It is an amenable number.

39961609 is a deficient number, since it is larger than the sum of its proper divisors (850295).

39961609 is an equidigital number, since it uses as much as digits as its factorization.

39961609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 850294.

The product of its (nonzero) digits is 78732, while the sum is 43.

The square root of 39961609 is about 6321.5195166985. The cubic root of 39961609 is about 341.8857415018.

The spelling of 39961609 in words is "thirty-nine million, nine hundred sixty-one thousand, six hundred nine".