1998200081 has 2 divisors, whose sum is σ = 1998200082. Its totient is φ = 1998200080.

The previous prime is 1998200051. The next prime is 1998200101. The reversal of 1998200081 is 1800028991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1532331025 + 465869056 = 39145^2 + 21584^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1998200081 is a prime.

It is a super-2 number, since 2×1998200081² = 7985607127416813122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1998200051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999100040 + 999100041.

It is an arithmetic number, because the mean of its divisors is an integer number (999100041).

Almost surely, 2^1998200081 is an apocalyptic number.

It is an amenable number.

1998200081 is a deficient number, since it is larger than the sum of its proper divisors (1).

1998200081 is an equidigital number, since it uses as much as digits as its factorization.

1998200081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 38.

The square root of 1998200081 is about 44701.2313141372. The cubic root of 1998200081 is about 1259.5429771494.

The spelling of 1998200081 in words is "one billion, nine hundred ninety-eight million, two hundred thousand, eighty-one".