39999971 has 4 divisors (see below), whose sum is σ = 43636344. Its totient is φ = 36363600.

The previous prime is 39999943. The next prime is 39999979. The reversal of 39999971 is 17999993.

It is a happy number.

39999971 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17999993 = 11 ⋅1636363.

It is a cyclic number.

It is not a de Polignac number, because 39999971 - 2⁶ = 39999907 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (39999979) 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 in 3 ways as a sum of consecutive naturals, for example, 1818170 + ... + 1818191.

It is an arithmetic number, because the mean of its divisors is an integer number (10909086).

Almost surely, 2^39999971 is an apocalyptic number.

39999971 is a deficient number, since it is larger than the sum of its proper divisors (3636373).

39999971 is a wasteful number, since it uses less digits than its factorization.

39999971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3636372.

The product of its digits is 1240029, while the sum is 56.

The square root of 39999971 is about 6324.5530276850. The cubic root of 39999971 is about 341.9951066865.

The spelling of 39999971 in words is "thirty-nine million, nine hundred ninety-nine thousand, nine hundred seventy-one".