39509945 has 4 divisors (see below), whose sum is σ = 47411940. Its totient is φ = 31607952.

The previous prime is 39509933. The next prime is 39509957. The reversal of 39509945 is 54990593.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (39509933) and next prime (39509957).

It can be written as a sum of positive squares in 2 ways, for example, as 15342889 + 24167056 = 3917^2 + 4916^2 .

It is a cyclic number.

It is not a de Polignac number, because 39509945 - 2¹⁶ = 39444409 is a prime.

It is a super-2 number, since 2×39509945² = 3122071507806050, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 39509896 and 39509905.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3950990 + ... + 3950999.

It is an arithmetic number, because the mean of its divisors is an integer number (11852985).

Almost surely, 2^39509945 is an apocalyptic number.

It is an amenable number.

39509945 is a deficient number, since it is larger than the sum of its proper divisors (7901995).

39509945 is an equidigital number, since it uses as much as digits as its factorization.

39509945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7901994.

The product of its (nonzero) digits is 218700, while the sum is 44.

The square root of 39509945 is about 6285.6936769143. The cubic root of 39509945 is about 340.5928095158.

The spelling of 39509945 in words is "thirty-nine million, five hundred nine thousand, nine hundred forty-five".