198999665 has 8 divisors (see below), whose sum is σ = 240991080. Its totient is φ = 157738752.

The previous prime is 198999649. The next prime is 198999677. The reversal of 198999665 is 566999891.

It can be written as a sum of positive squares in 4 ways, for example, as 21603904 + 177395761 = 4648^2 + 13319^2 .

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 198999665 - 2⁴ = 198999649 is a prime.

It is a super-2 number, since 2×198999665² = 79201733340224450, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 198999598 and 198999607.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 182024 + ... + 183113.

It is an arithmetic number, because the mean of its divisors is an integer number (30123885).

Almost surely, 2^198999665 is an apocalyptic number.

It is an amenable number.

198999665 is a deficient number, since it is larger than the sum of its proper divisors (41991415).

198999665 is a wasteful number, since it uses less digits than its factorization.

198999665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 365251.

The product of its digits is 9447840, while the sum is 62.

The square root of 198999665 is about 14106.7241059007. The cubic root of 198999665 is about 583.8269184730.

The spelling of 198999665 in words is "one hundred ninety-eight million, nine hundred ninety-nine thousand, six hundred sixty-five".