198316581 has 4 divisors (see below), whose sum is σ = 264422112. Its totient is φ = 132211052.

The previous prime is 198316567. The next prime is 198316609. The reversal of 198316581 is 185613891.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 198316581 - 2¹⁹ = 197792293 is a prime.

It is a super-3 number, since 3×198316581³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198316541) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33052761 + ... + 33052766.

It is an arithmetic number, because the mean of its divisors is an integer number (66105528).

Almost surely, 2^198316581 is an apocalyptic number.

It is an amenable number.

198316581 is a deficient number, since it is larger than the sum of its proper divisors (66105531).

198316581 is an equidigital number, since it uses as much as digits as its factorization.

198316581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66105530.

The product of its digits is 51840, while the sum is 42.

The square root of 198316581 is about 14082.4920024831. The cubic root of 198316581 is about 583.1581401149.

The spelling of 198316581 in words is "one hundred ninety-eight million, three hundred sixteen thousand, five hundred eighty-one".