21083191 has 2 divisors, whose sum is σ = 21083192. Its totient is φ = 21083190.

The previous prime is 21083189. The next prime is 21083197. The reversal of 21083191 is 19138012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21083191 - 2¹ = 21083189 is a prime.

Together with 21083189, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21083197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10541595 + 10541596.

It is an arithmetic number, because the mean of its divisors is an integer number (10541596).

Almost surely, 2^21083191 is an apocalyptic number.

21083191 is a deficient number, since it is larger than the sum of its proper divisors (1).

21083191 is an equidigital number, since it uses as much as digits as its factorization.

21083191 is an evil number, because the sum of its binary digits is even.

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

The square root of 21083191 is about 4591.6436055077. The cubic root of 21083191 is about 276.2562513685.

The spelling of 21083191 in words is "twenty-one million, eighty-three thousand, one hundred ninety-one".