198921965 has 16 divisors (see below), whose sum is σ = 260680896. Its totient is φ = 144518400.

The previous prime is 198921959. The next prime is 198921971. The reversal of 198921965 is 569129891.

It is an interprime number because it is at equal distance from previous prime (198921959) and next prime (198921971).

It is a de Polignac number, because none of the positive numbers 2^k-198921965 is a prime.

It is a super-2 number, since 2×198921965² = 79139896318922450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 102050 + ... + 103980.

It is an arithmetic number, because the mean of its divisors is an integer number (16292556).

Almost surely, 2^198921965 is an apocalyptic number.

It is an amenable number.

198921965 is a deficient number, since it is larger than the sum of its proper divisors (61758931).

198921965 is a wasteful number, since it uses less digits than its factorization.

198921965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3820.

The product of its digits is 349920, while the sum is 50.

The square root of 198921965 is about 14103.9698312213. The cubic root of 198921965 is about 583.7509229398.

The spelling of 198921965 in words is "one hundred ninety-eight million, nine hundred twenty-one thousand, nine hundred sixty-five".