39890491 has 2 divisors, whose sum is σ = 39890492. Its totient is φ = 39890490.

The previous prime is 39890489. The next prime is 39890509. The reversal of 39890491 is 19409893.

39890491 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 is an emirp because it is prime and its reverse (19409893) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 39890491 - 2¹ = 39890489 is a prime.

Together with 39890489, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (39890471) 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, 19945245 + 19945246.

It is an arithmetic number, because the mean of its divisors is an integer number (19945246).

Almost surely, 2^39890491 is an apocalyptic number.

39890491 is a deficient number, since it is larger than the sum of its proper divisors (1).

39890491 is an equidigital number, since it uses as much as digits as its factorization.

39890491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 69984, while the sum is 43.

The square root of 39890491 is about 6315.8919401776. The cubic root of 39890491 is about 341.6828078302.

The spelling of 39890491 in words is "thirty-nine million, eight hundred ninety thousand, four hundred ninety-one".