20198181 has 16 divisors (see below), whose sum is σ = 28036800. Its totient is φ = 12918528.

The previous prime is 20198147. The next prime is 20198183. The reversal of 20198181 is 18189102.

It is not a de Polignac number, because 20198181 - 2⁷ = 20198053 is a prime.

It is a super-2 number, since 2×20198181² = 815933031417522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20198183) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14925 + ... + 16221.

It is an arithmetic number, because the mean of its divisors is an integer number (1752300).

Almost surely, 2^20198181 is an apocalyptic number.

It is an amenable number.

20198181 is a deficient number, since it is larger than the sum of its proper divisors (7838619).

20198181 is a wasteful number, since it uses less digits than its factorization.

20198181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1508.

The product of its (nonzero) digits is 1152, while the sum is 30.

The square root of 20198181 is about 4494.2386451990. The cubic root of 20198181 is about 272.3353931103.

The spelling of 20198181 in words is "twenty million, one hundred ninety-eight thousand, one hundred eighty-one".