39673681 has 2 divisors, whose sum is σ = 39673682. Its totient is φ = 39673680.

The previous prime is 39673663. The next prime is 39673727. The reversal of 39673681 is 18637693.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39627025 + 46656 = 6295^2 + 216^2 .

It is an emirp because it is prime and its reverse (18637693) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 39673681 - 2⁹ = 39673169 is a prime.

It is a super-2 number, since 2×39673681² = 3148001928179522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (39673181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19836840 + 19836841.

It is an arithmetic number, because the mean of its divisors is an integer number (19836841).

Almost surely, 2^39673681 is an apocalyptic number.

It is an amenable number.

39673681 is a deficient number, since it is larger than the sum of its proper divisors (1).

39673681 is an equidigital number, since it uses as much as digits as its factorization.

39673681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 163296, while the sum is 43.

The square root of 39673681 is about 6298.7047081126. The cubic root of 39673681 is about 341.0626527810.

The spelling of 39673681 in words is "thirty-nine million, six hundred seventy-three thousand, six hundred eighty-one".