20198131 has 4 divisors (see below), whose sum is σ = 20207392. Its totient is φ = 20188872.

The previous prime is 20198111. The next prime is 20198147. The reversal of 20198131 is 13189102.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 20198131 - 2⁵ = 20198099 is a prime.

It is a super-2 number, since 2×20198131² = 815928991786322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20198096 and 20198105.

It is not an unprimeable number, because it can be changed into a prime (20198111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 646 + ... + 6388.

It is an arithmetic number, because the mean of its divisors is an integer number (5051848).

Almost surely, 2^20198131 is an apocalyptic number.

20198131 is a deficient number, since it is larger than the sum of its proper divisors (9261).

20198131 is an equidigital number, since it uses as much as digits as its factorization.

20198131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9260.

The product of its (nonzero) digits is 432, while the sum is 25.

The square root of 20198131 is about 4494.2330825181. The cubic root of 20198131 is about 272.3351683907.

The spelling of 20198131 in words is "twenty million, one hundred ninety-eight thousand, one hundred thirty-one".