21212341 has 4 divisors (see below), whose sum is σ = 22328800. Its totient is φ = 20095884.

The previous prime is 21212297. The next prime is 21212353. The reversal of 21212341 is 14321212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21212341 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212641) 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 3 ways as a sum of consecutive naturals, for example, 558201 + ... + 558238.

It is an arithmetic number, because the mean of its divisors is an integer number (5582200).

Almost surely, 2^21212341 is an apocalyptic number.

It is an amenable number.

21212341 is a deficient number, since it is larger than the sum of its proper divisors (1116459).

21212341 is a wasteful number, since it uses less digits than its factorization.

21212341 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1116458.

The product of its digits is 96, while the sum is 16.

The square root of 21212341 is about 4605.6857252748. The cubic root of 21212341 is about 276.8191941330.

Adding to 21212341 its reverse (14321212), we get a palindrome (35533553).

The spelling of 21212341 in words is "twenty-one million, two hundred twelve thousand, three hundred forty-one".