198620809 has 8 divisors (see below), whose sum is σ = 213186600. Its totient is φ = 184375296.

The previous prime is 198620803. The next prime is 198620837. The reversal of 198620809 is 908026891.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 131331600 + 67289209 = 11460^2 + 8203^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 198620809 - 2⁵ = 198620777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (198620803) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 78784 + ... + 81265.

It is an arithmetic number, because the mean of its divisors is an integer number (26648325).

Almost surely, 2^198620809 is an apocalyptic number.

It is an amenable number.

198620809 is a deficient number, since it is larger than the sum of its proper divisors (14565791).

198620809 is a wasteful number, since it uses less digits than its factorization.

198620809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160139.

The product of its (nonzero) digits is 62208, while the sum is 43.

The square root of 198620809 is about 14093.2895024547. The cubic root of 198620809 is about 583.4561861157.

The spelling of 198620809 in words is "one hundred ninety-eight million, six hundred twenty thousand, eight hundred nine".