391738985 has 16 divisors (see below), whose sum is σ = 513482112. Its totient is φ = 284534400.

The previous prime is 391738981. The next prime is 391738999. The reversal of 391738985 is 589837193.

It is a happy number.

It is not a de Polignac number, because 391738985 - 2² = 391738981 is a prime.

It is not an unprimeable number, because it can be changed into a prime (391738981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42980 + ... + 51290.

It is an arithmetic number, because the mean of its divisors is an integer number (32092632).

Almost surely, 2^391738985 is an apocalyptic number.

It is an amenable number.

391738985 is a deficient number, since it is larger than the sum of its proper divisors (121743127).

391738985 is a wasteful number, since it uses less digits than its factorization.

391738985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9184.

The product of its digits is 1632960, while the sum is 53.

The square root of 391738985 is about 19792.3971514317. The cubic root of 391738985 is about 731.6986682373.

The spelling of 391738985 in words is "three hundred ninety-one million, seven hundred thirty-eight thousand, nine hundred eighty-five".