999998000001 has 567 divisors, whose sum is σ = 2133496062873. Its totient is φ = 466559533440.

The previous prime is 999997999981. The next prime is 999998000009. The reversal of 999998000001 is 100000899999.

The square root of 999998000001 is 999999.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 4153673601 + 995844326400 = 64449^2 + 997920^2 .

It is a tau number, because it is divible by the number of its divisors (567).

It is not a de Polignac number, because 999998000001 - 2⁹ = 999997999489 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (999998000009) 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 in 566 ways as a sum of consecutive naturals, for example, 27026972955 + ... + 27026972991.

Almost surely, 2^999998000001 is an apocalyptic number.

999998000001 is a gapful number since it is divisible by the number (91) formed by its first and last digit.

999998000001 is the 999999-th square number.

999998000001 is the 500000-th centered octagonal number.

It is an amenable number.

999998000001 is an abundant number, since it is smaller than the sum of its proper divisors (1133498062872).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

999998000001 is a wasteful number, since it uses less digits than its factorization.

999998000001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154 (or 71 counting only the distinct ones).

The product of its (nonzero) digits is 472392, while the sum is 54.

It can be divided in two parts, 9999 and 98000001, that added together give a square (98010000 = 9900²).

The spelling of 999998000001 in words is "nine hundred ninety-nine billion, nine hundred ninety-eight million, one", and thus it is an aban number.