21600191 has 2 divisors, whose sum is σ = 21600192. Its totient is φ = 21600190.

The previous prime is 21600181. The next prime is 21600209. The reversal of 21600191 is 19100612.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21600191 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21600121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10800095 + 10800096.

It is an arithmetic number, because the mean of its divisors is an integer number (10800096).

Almost surely, 2^21600191 is an apocalyptic number.

21600191 is a deficient number, since it is larger than the sum of its proper divisors (1).

21600191 is an equidigital number, since it uses as much as digits as its factorization.

21600191 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108, while the sum is 20.

The square root of 21600191 is about 4647.6005637318. The cubic root of 21600191 is about 278.4961508879.

The spelling of 21600191 in words is "twenty-one million, six hundred thousand, one hundred ninety-one".