21422191 has 8 divisors (see below), whose sum is σ = 24827904. Its totient is φ = 18102840.

The previous prime is 21422143. The next prime is 21422221. The reversal of 21422191 is 19122412.

21422191 is nontrivially palindromic in base 12.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21422191 - 2⁹ = 21421679 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 (21426191) 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 7 ways as a sum of consecutive naturals, for example, 21055 + ... + 22048.

It is an arithmetic number, because the mean of its divisors is an integer number (3103488).

Almost surely, 2^21422191 is an apocalyptic number.

21422191 is a deficient number, since it is larger than the sum of its proper divisors (3405713).

21422191 is an equidigital number, since it uses as much as digits as its factorization.

21422191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43181.

The product of its digits is 288, while the sum is 22.

The square root of 21422191 is about 4628.4112825029. The cubic root of 21422191 is about 277.7290417550.

The spelling of 21422191 in words is "twenty-one million, four hundred twenty-two thousand, one hundred ninety-one".