21304054421 has 4 divisors (see below), whose sum is σ = 22942827852. Its totient is φ = 19665280992.

The previous prime is 21304054397. The next prime is 21304054427. The reversal of 21304054421 is 12445040312.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1847710225 + 19456344196 = 42985^2 + 139486^2 .

It is a cyclic number.

It is not a de Polignac number, because 21304054421 - 2¹⁸ = 21303792277 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 (21304054427) 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, 819386696 + ... + 819386721.

It is an arithmetic number, because the mean of its divisors is an integer number (5735706963).

Almost surely, 2^21304054421 is an apocalyptic number.

It is an amenable number.

21304054421 is a deficient number, since it is larger than the sum of its proper divisors (1638773431).

21304054421 is a wasteful number, since it uses less digits than its factorization.

21304054421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1638773430.

The product of its (nonzero) digits is 3840, while the sum is 26.

Adding to 21304054421 its reverse (12445040312), we get a palindrome (33749094733).

The spelling of 21304054421 in words is "twenty-one billion, three hundred four million, fifty-four thousand, four hundred twenty-one".