999998869 has 2 divisors, whose sum is σ = 999998870. Its totient is φ = 999998868.

The previous prime is 999998863. The next prime is 999998903. The reversal of 999998869 is 968899999.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 824436369 + 175562500 = 28713^2 + 13250^2 .

It is a cyclic number.

It is not a de Polignac number, because 999998869 - 2¹⁷ = 999867797 is a prime.

It is a super-2 number, since 2×999998869² = 1999995476002558322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 999998795 and 999998804.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999998863) 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 as a sum of consecutive naturals, namely, 499999434 + 499999435.

It is an arithmetic number, because the mean of its divisors is an integer number (499999435).

Almost surely, 2^999998869 is an apocalyptic number.

It is an amenable number.

999998869 is a deficient number, since it is larger than the sum of its proper divisors (1).

999998869 is an equidigital number, since it uses as much as digits as its factorization.

999998869 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 204073344, while the sum is 76.

The square root of 999998869 is about 31622.7587189986. The cubic root of 999998869 is about 999.9996229999. Note that the first 3 decimals are identical.

The spelling of 999998869 in words is "nine hundred ninety-nine million, nine hundred ninety-eight thousand, eight hundred sixty-nine".