21324404421 has 24 divisors (see below), whose sum is σ = 31026228480. Its totient is φ = 14112942336.

The previous prime is 21324404411. The next prime is 21324404441. The reversal of 21324404421 is 12440442312.

21324404421 is a `hidden beast` number, since 213 + 2 + 4 + 4 + 0 + 442 + 1 = 666.

It is not a de Polignac number, because 21324404421 - 2⁹ = 21324403909 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21324404411) 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 23 ways as a sum of consecutive naturals, for example, 1355020 + ... + 1370666.

It is an arithmetic number, because the mean of its divisors is an integer number (1292759520).

Almost surely, 2^21324404421 is an apocalyptic number.

It is an amenable number.

21324404421 is a deficient number, since it is larger than the sum of its proper divisors (9701824059).

21324404421 is a wasteful number, since it uses less digits than its factorization.

21324404421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16745 (or 16742 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 27.

Adding to 21324404421 its reverse (12440442312), we get a palindrome (33764846733).

The spelling of 21324404421 in words is "twenty-one billion, three hundred twenty-four million, four hundred four thousand, four hundred twenty-one".