21344191 has 4 divisors (see below), whose sum is σ = 23284584. Its totient is φ = 19403800.

The previous prime is 21344173. The next prime is 21344209. The reversal of 21344191 is 19144312.

It is a happy number.

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

It is an interprime number because it is at equal distance from previous prime (21344173) and next prime (21344209).

It is a cyclic number.

It is not a de Polignac number, because 21344191 - 2⁵ = 21344159 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 (21344131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 970180 + ... + 970201.

It is an arithmetic number, because the mean of its divisors is an integer number (5821146).

Almost surely, 2^21344191 is an apocalyptic number.

21344191 is a deficient number, since it is larger than the sum of its proper divisors (1940393).

21344191 is a wasteful number, since it uses less digits than its factorization.

21344191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1940392.

The product of its digits is 864, while the sum is 25.

The square root of 21344191 is about 4619.9773808970. The cubic root of 21344191 is about 277.3915535451.

It can be divided in two parts, 21344 and 191, that multiplied together give a palindrome (4076704).

The spelling of 21344191 in words is "twenty-one million, three hundred forty-four thousand, one hundred ninety-one".