21204424229 has 2 divisors, whose sum is σ = 21204424230. Its totient is φ = 21204424228.

The previous prime is 21204424217. The next prime is 21204424237. The reversal of 21204424229 is 92242440212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19774828129 + 1429596100 = 140623^2 + 37810^2 .

It is a cyclic number.

It is not a de Polignac number, because 21204424229 - 2²⁰ = 21203375653 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21204424195 and 21204424204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21204424729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10602212114 + 10602212115.

It is an arithmetic number, because the mean of its divisors is an integer number (10602212115).

Almost surely, 2^21204424229 is an apocalyptic number.

It is an amenable number.

21204424229 is a deficient number, since it is larger than the sum of its proper divisors (1).

21204424229 is an equidigital number, since it uses as much as digits as its factorization.

21204424229 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18432, while the sum is 32.

The spelling of 21204424229 in words is "twenty-one billion, two hundred four million, four hundred twenty-four thousand, two hundred twenty-nine".