198420581 has 8 divisors (see below), whose sum is σ = 207381720. Its totient is φ = 189600768.

The previous prime is 198420571. The next prime is 198420589. The reversal of 198420581 is 185024891.

It can be written as a sum of positive squares in 4 ways, for example, as 75099556 + 123321025 = 8666^2 + 11105^2 .

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 198420581 - 2¹⁸ = 198158437 is a prime.

It is a super-2 number, since 2×198420581² = 78741453928755122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198420589) 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, 32456 + ... + 38081.

It is an arithmetic number, because the mean of its divisors is an integer number (25922715).

Almost surely, 2^198420581 is an apocalyptic number.

It is an amenable number.

198420581 is a deficient number, since it is larger than the sum of its proper divisors (8961139).

198420581 is an equidigital number, since it uses as much as digits as its factorization.

198420581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70663.

The product of its (nonzero) digits is 23040, while the sum is 38.

The square root of 198420581 is about 14086.1840467885. The cubic root of 198420581 is about 583.2600610733.

The spelling of 198420581 in words is "one hundred ninety-eight million, four hundred twenty thousand, five hundred eighty-one".