21441191 has 2 divisors, whose sum is σ = 21441192. Its totient is φ = 21441190.

The previous prime is 21441169. The next prime is 21441193. The reversal of 21441191 is 19114412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21441191 - 2¹⁸ = 21179047 is a prime.

Together with 21441193, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21441193) 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 as a sum of consecutive naturals, namely, 10720595 + 10720596.

It is an arithmetic number, because the mean of its divisors is an integer number (10720596).

Almost surely, 2^21441191 is an apocalyptic number.

21441191 is a deficient number, since it is larger than the sum of its proper divisors (1).

21441191 is an equidigital number, since it uses as much as digits as its factorization.

21441191 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 288, while the sum is 23.

The square root of 21441191 is about 4630.4633677419. The cubic root of 21441191 is about 277.8111263014.

The spelling of 21441191 in words is "twenty-one million, four hundred forty-one thousand, one hundred ninety-one".