39939181 has 2 divisors, whose sum is σ = 39939182. Its totient is φ = 39939180.

The previous prime is 39939173. The next prime is 39939209. The reversal of 39939181 is 18193993.

39939181 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21706281 + 18232900 = 4659^2 + 4270^2 .

It is a cyclic number.

It is not a de Polignac number, because 39939181 - 2³ = 39939173 is a prime.

It is a super-2 number, since 2×39939181² = 3190276357901522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39939281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19969590 + 19969591.

It is an arithmetic number, because the mean of its divisors is an integer number (19969591).

Almost surely, 2^39939181 is an apocalyptic number.

It is an amenable number.

39939181 is a deficient number, since it is larger than the sum of its proper divisors (1).

39939181 is an equidigital number, since it uses as much as digits as its factorization.

39939181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 52488, while the sum is 43.

The square root of 39939181 is about 6319.7453271473. The cubic root of 39939181 is about 341.8217697004.

The spelling of 39939181 in words is "thirty-nine million, nine hundred thirty-nine thousand, one hundred eighty-one".