991313685 has 48 divisors (see below), whose sum is σ = 1796715648. Its totient is φ = 504662400.

The previous prime is 991313683. The next prime is 991313711. The reversal of 991313685 is 586313199.

It is not a de Polignac number, because 991313685 - 2¹ = 991313683 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 991313685.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991313683) 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 47 ways as a sum of consecutive naturals, for example, 838795 + ... + 839975.

It is an arithmetic number, because the mean of its divisors is an integer number (37431576).

Almost surely, 2^991313685 is an apocalyptic number.

It is an amenable number.

991313685 is a deficient number, since it is larger than the sum of its proper divisors (805401963).

991313685 is a wasteful number, since it uses less digits than its factorization.

991313685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2026 (or 2023 counting only the distinct ones).

The product of its digits is 174960, while the sum is 45.

The square root of 991313685 is about 31485.1343494037. The cubic root of 991313685 is about 997.0961374109.

The spelling of 991313685 in words is "nine hundred ninety-one million, three hundred thirteen thousand, six hundred eighty-five".