198117785515 has 16 divisors (see below), whose sum is σ = 257562260928. Its totient is φ = 145426294656.

The previous prime is 198117785513. The next prime is 198117785521. The reversal of 198117785515 is 515587711891.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 198117785515 - 2¹ = 198117785513 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 198117785515.

It is not an unprimeable number, because it can be changed into a prime (198117785513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9114792 + ... + 9136501.

It is an arithmetic number, because the mean of its divisors is an integer number (16097641308).

Almost surely, 2^198117785515 is an apocalyptic number.

198117785515 is a deficient number, since it is larger than the sum of its proper divisors (59444475413).

198117785515 is a wasteful number, since it uses less digits than its factorization.

198117785515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18251478.

The product of its digits is 3528000, while the sum is 58.

The spelling of 198117785515 in words is "one hundred ninety-eight billion, one hundred seventeen million, seven hundred eighty-five thousand, five hundred fifteen".