999998881 has 16 divisors (see below), whose sum is σ = 1156896000. Its totient is φ = 846655488.

The previous prime is 999998869. The next prime is 999998903. The reversal of 999998881 is 188899999.

It is not a de Polignac number, because 999998881 - 2⁹ = 999998369 is a prime.

It is a super-2 number, since 2×999998881² = 1999995524002504322, which contains 22 as substring.

It is a nialpdrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 999998881.

It is not an unprimeable number, because it can be changed into a prime (999998801) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 322185 + ... + 325273.

It is an arithmetic number, because the mean of its divisors is an integer number (72306000).

Almost surely, 2^999998881 is an apocalyptic number.

It is an amenable number.

999998881 is a deficient number, since it is larger than the sum of its proper divisors (156897119).

999998881 is a wasteful number, since it uses less digits than its factorization.

999998881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3648.

The product of its digits is 30233088, while the sum is 70.

The square root of 999998881 is about 31622.7589087353. The cubic root of 999998881 is about 999.9996269999. Note that the first 3 decimals are identical.

The spelling of 999998881 in words is "nine hundred ninety-nine million, nine hundred ninety-eight thousand, eight hundred eighty-one".