21204224399 has 2 divisors, whose sum is σ = 21204224400. Its totient is φ = 21204224398.

The previous prime is 21204224369. The next prime is 21204224407. The reversal of 21204224399 is 99342240212.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21204224399 is a prime.

It is a super-2 number, since 2×21204224399² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21204224369) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10602112199 + 10602112200.

It is an arithmetic number, because the mean of its divisors is an integer number (10602112200).

Almost surely, 2^21204224399 is an apocalyptic number.

21204224399 is a deficient number, since it is larger than the sum of its proper divisors (1).

21204224399 is an equidigital number, since it uses as much as digits as its factorization.

21204224399 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 62208, while the sum is 38.

The spelling of 21204224399 in words is "twenty-one billion, two hundred four million, two hundred twenty-four thousand, three hundred ninety-nine".