20195191 has 4 divisors (see below), whose sum is σ = 20269984. Its totient is φ = 20120400.

The previous prime is 20195179. The next prime is 20195221. The reversal of 20195191 is 19159102.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20195191 - 2²³ = 11806583 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 (20195111) 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, 36990 + ... + 37531.

It is an arithmetic number, because the mean of its divisors is an integer number (5067496).

Almost surely, 2^20195191 is an apocalyptic number.

20195191 is a deficient number, since it is larger than the sum of its proper divisors (74793).

20195191 is an equidigital number, since it uses as much as digits as its factorization.

20195191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74792.

The product of its (nonzero) digits is 810, while the sum is 28.

The square root of 20195191 is about 4493.9059847754. The cubic root of 20195191 is about 272.3219542268.

The spelling of 20195191 in words is "twenty million, one hundred ninety-five thousand, one hundred ninety-one".