39539945 has 4 divisors (see below), whose sum is σ = 47447940. Its totient is φ = 31631952.

The previous prime is 39539887. The next prime is 39539947. The reversal of 39539945 is 54993593.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54993593 = 607 ⋅90599.

It can be written as a sum of positive squares in 2 ways, for example, as 7311616 + 32228329 = 2704^2 + 5677^2 .

It is a cyclic number.

It is not a de Polignac number, because 39539945 - 2¹⁰ = 39538921 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 39539945.

It is not an unprimeable number, because it can be changed into a prime (39539947) 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, 3953990 + ... + 3953999.

It is an arithmetic number, because the mean of its divisors is an integer number (11861985).

Almost surely, 2^39539945 is an apocalyptic number.

It is an amenable number.

39539945 is a deficient number, since it is larger than the sum of its proper divisors (7907995).

39539945 is an equidigital number, since it uses as much as digits as its factorization.

39539945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7907994.

The product of its digits is 656100, while the sum is 47.

The square root of 39539945 is about 6288.0795955522. The cubic root of 39539945 is about 340.6789920305.

The spelling of 39539945 in words is "thirty-nine million, five hundred thirty-nine thousand, nine hundred forty-five".