39947749 has 2 divisors, whose sum is σ = 39947750. Its totient is φ = 39947748.

The previous prime is 39947689. The next prime is 39947759. The reversal of 39947749 is 94774993.

39947749 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39917124 + 30625 = 6318^2 + 175^2 .

It is an emirp because it is prime and its reverse (94774993) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 39947749 - 2¹⁵ = 39914981 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 39947696 and 39947705.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39947759) 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, 19973874 + 19973875.

It is an arithmetic number, because the mean of its divisors is an integer number (19973875).

Almost surely, 2^39947749 is an apocalyptic number.

It is an amenable number.

39947749 is a deficient number, since it is larger than the sum of its proper divisors (1).

39947749 is an equidigital number, since it uses as much as digits as its factorization.

39947749 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1714608, while the sum is 52.

The square root of 39947749 is about 6320.4231662128. The cubic root of 39947749 is about 341.8462111924.

The spelling of 39947749 in words is "thirty-nine million, nine hundred forty-seven thousand, seven hundred forty-nine".