991580317 has 12 divisors (see below), whose sum is σ = 1242200316. Its totient is φ = 784546560.

The previous prime is 991580287. The next prime is 991580321. The reversal of 991580317 is 713085199.

991580317 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 183087961 + 808492356 = 13531^2 + 28434^2 .

It is a de Polignac number, because none of the positive numbers 2^k-991580317 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991580357) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 777684 + ... + 778957.

It is an arithmetic number, because the mean of its divisors is an integer number (103516693).

Almost surely, 2^991580317 is an apocalyptic number.

It is an amenable number.

991580317 is a deficient number, since it is larger than the sum of its proper divisors (250619999).

991580317 is a wasteful number, since it uses less digits than its factorization.

991580317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1556668 (or 1556661 counting only the distinct ones).

The product of its (nonzero) digits is 68040, while the sum is 43.

The square root of 991580317 is about 31489.3683169415. The cubic root of 991580317 is about 997.1855251628.

The spelling of 991580317 in words is "nine hundred ninety-one million, five hundred eighty thousand, three hundred seventeen".