39989381 has 2 divisors, whose sum is σ = 39989382. Its totient is φ = 39989380.

The previous prime is 39989377. The next prime is 39989393. The reversal of 39989381 is 18398993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31192225 + 8797156 = 5585^2 + 2966^2 .

It is a cyclic number.

It is not a de Polignac number, because 39989381 - 2² = 39989377 is a prime.

It is a super-2 number, since 2×39989381² = 3198301185526322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39989311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19994690 + 19994691.

It is an arithmetic number, because the mean of its divisors is an integer number (19994691).

Almost surely, 2^39989381 is an apocalyptic number.

It is an amenable number.

39989381 is a deficient number, since it is larger than the sum of its proper divisors (1).

39989381 is an equidigital number, since it uses as much as digits as its factorization.

39989381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 419904, while the sum is 50.

The square root of 39989381 is about 6323.7157589506. The cubic root of 39989381 is about 341.9649229326.

The spelling of 39989381 in words is "thirty-nine million, nine hundred eighty-nine thousand, three hundred eighty-one".