991927285 has 8 divisors (see below), whose sum is σ = 1206618840. Its totient is φ = 782671104.

The previous prime is 991927259. The next prime is 991927289. The reversal of 991927285 is 582729199.

It can be written as a sum of positive squares in 4 ways, for example, as 232318564 + 759608721 = 15242^2 + 27561^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 991927285 - 2⁵ = 991927253 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991927289) 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, 1358440 + ... + 1359169.

It is an arithmetic number, because the mean of its divisors is an integer number (150827355).

Almost surely, 2^991927285 is an apocalyptic number.

It is an amenable number.

991927285 is a deficient number, since it is larger than the sum of its proper divisors (214691555).

991927285 is a wasteful number, since it uses less digits than its factorization.

991927285 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2717687.

The product of its digits is 816480, while the sum is 52.

The square root of 991927285 is about 31494.8771231132. The cubic root of 991927285 is about 997.3018213799.

The spelling of 991927285 in words is "nine hundred ninety-one million, nine hundred twenty-seven thousand, two hundred eighty-five".