39947893 has 2 divisors, whose sum is σ = 39947894. Its totient is φ = 39947892.

The previous prime is 39947891. The next prime is 39947939. The reversal of 39947893 is 39874993.

39947893 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., 34597924 + 5349969 = 5882^2 + 2313^2 .

It is an emirp because it is prime and its reverse (39874993) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 39947893 - 2¹ = 39947891 is a prime.

Together with 39947891, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 39947893.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39947891) 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, 19973946 + 19973947.

It is an arithmetic number, because the mean of its divisors is an integer number (19973947).

Almost surely, 2^39947893 is an apocalyptic number.

It is an amenable number.

39947893 is a deficient number, since it is larger than the sum of its proper divisors (1).

39947893 is an equidigital number, since it uses as much as digits as its factorization.

39947893 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1469664, while the sum is 52.

The square root of 39947893 is about 6320.4345578449. The cubic root of 39947893 is about 341.8466219439.

Subtracting from 39947893 its reverse (39874993), we obtain a square (72900 = 270²).

The spelling of 39947893 in words is "thirty-nine million, nine hundred forty-seven thousand, eight hundred ninety-three".