20010191 has 4 divisors (see below), whose sum is σ = 20019384. Its totient is φ = 20001000.

The previous prime is 20010187. The next prime is 20010197. The reversal of 20010191 is 19101002.

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 20010191 - 2² = 20010187 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20010197) 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, 716 + ... + 6366.

It is an arithmetic number, because the mean of its divisors is an integer number (5004846).

Almost surely, 2^20010191 is an apocalyptic number.

20010191 is a deficient number, since it is larger than the sum of its proper divisors (9193).

20010191 is an equidigital number, since it uses as much as digits as its factorization.

20010191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9192.

The product of its (nonzero) digits is 18, while the sum is 14.

The square root of 20010191 is about 4473.2751983306. The cubic root of 20010191 is about 271.4878582141.

Adding to 20010191 its reverse (19101002), we get a palindrome (39111193).

The spelling of 20010191 in words is "twenty million, ten thousand, one hundred ninety-one".