391765489 has 4 divisors (see below), whose sum is σ = 393795556. Its totient is φ = 389735424.

The previous prime is 391765483. The next prime is 391765499. The reversal of 391765489 is 984567193.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 38626225 + 353139264 = 6215^2 + 18792^2 .

It is a cyclic number.

It is not a de Polignac number, because 391765489 - 2⁵ = 391765457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (391765483) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1014744 + ... + 1015129.

It is an arithmetic number, because the mean of its divisors is an integer number (98448889).

Almost surely, 2^391765489 is an apocalyptic number.

It is an amenable number.

391765489 is a deficient number, since it is larger than the sum of its proper divisors (2030067).

391765489 is a wasteful number, since it uses less digits than its factorization.

391765489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2030066.

The product of its digits is 1632960, while the sum is 52.

The square root of 391765489 is about 19793.0666901317. The cubic root of 391765489 is about 731.7151694493.

The spelling of 391765489 in words is "three hundred ninety-one million, seven hundred sixty-five thousand, four hundred eighty-nine".