199720098 has 18 divisors (see below), whose sum is σ = 432856827. Its totient is φ = 66553380.

The previous prime is 199720069. The next prime is 199720177. The reversal of 199720098 is 890027991.

It can be written as a sum of positive squares in only one way, i.e., 99860049 + 99860049 = 9993^2 + 9993^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=9993.

It is an unprimeable number.

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 8 ways as a sum of consecutive naturals, for example, 58293 + ... + 61623.

Almost surely, 2^199720098 is an apocalyptic number.

199720098 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

199720098 is an abundant number, since it is smaller than the sum of its proper divisors (233136729).

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

199720098 is an frugal number, since it uses more digits than its factorization.

199720098 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6670 (or 3336 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 45.

The square root of 199720098 is about 14132.2361287943. The cubic root of 199720098 is about 584.5306074711.

The spelling of 199720098 in words is "one hundred ninety-nine million, seven hundred twenty thousand, ninety-eight".