991345 has 8 divisors (see below), whose sum is σ = 1195200. Its totient is φ = 789360.

The previous prime is 991343. The next prime is 991357. The reversal of 991345 is 543199.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 991345 - 2¹ = 991343 is a prime.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991343) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1356 + ... + 1954.

It is an arithmetic number, because the mean of its divisors is an integer number (149400).

2⁹⁹¹³⁴⁵ is an apocalyptic number.

It is an amenable number.

991345 is a deficient number, since it is larger than the sum of its proper divisors (203855).

991345 is a wasteful number, since it uses less digits than its factorization.

991345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 935.

The product of its digits is 4860, while the sum is 31.

The square root of 991345 is about 995.6630956302. The cubic root of 991345 is about 99.7106636522.

It can be divided in two parts, 99 and 1345, that added together give a square (1444 = 38²).

The spelling of 991345 in words is "nine hundred ninety-one thousand, three hundred forty-five".