198771890 has 16 divisors (see below), whose sum is σ = 358166232. Its totient is φ = 79425024.

The previous prime is 198771841. The next prime is 198771893. The reversal of 198771890 is 98177891.

It can be written as a sum of positive squares in 4 ways, for example, as 163047361 + 35724529 = 12769^2 + 5977^2 .

It is not an unprimeable number, because it can be changed into a prime (198771893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2 + ... + 19938.

Almost surely, 2^198771890 is an apocalyptic number.

198771890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

198771890 is a deficient number, since it is larger than the sum of its proper divisors (159394342).

198771890 is a wasteful number, since it uses less digits than its factorization.

198771890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20941.

The product of its (nonzero) digits is 254016, while the sum is 50.

The square root of 198771890 is about 14098.6485167905. The cubic root of 198771890 is about 583.6040840185.

The spelling of 198771890 in words is "one hundred ninety-eight million, seven hundred seventy-one thousand, eight hundred ninety".