999991285 has 8 divisors (see below), whose sum is σ = 1200356280. Its totient is φ = 799748544.

The previous prime is 999991283. The next prime is 999991301. The reversal of 999991285 is 582199999.

It can be written as a sum of positive squares in 4 ways, for example, as 25989604 + 974001681 = 5098^2 + 31209^2 .

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 999991285 - 2¹ = 999991283 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999991283) 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, 11482 + ... + 46171.

It is an arithmetic number, because the mean of its divisors is an integer number (150044535).

Almost surely, 2^999991285 is an apocalyptic number.

It is an amenable number.

999991285 is a deficient number, since it is larger than the sum of its proper divisors (200364995).

999991285 is a wasteful number, since it uses less digits than its factorization.

999991285 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61127.

The product of its digits is 4723920, while the sum is 61.

The square root of 999991285 is about 31622.6388051345. The cubic root of 999991285 is about 999.9970949916.

The spelling of 999991285 in words is "nine hundred ninety-nine million, nine hundred ninety-one thousand, two hundred eighty-five".