21229429567817 has 2 divisors, whose sum is σ = 21229429567818. Its totient is φ = 21229429567816.

The previous prime is 21229429567769. The next prime is 21229429567883. The reversal of 21229429567817 is 71876592492212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21218147091856 + 11282475961 = 4606316^2 + 106219^2 .

It is a cyclic number.

It is not a de Polignac number, because 21229429567817 - 2¹² = 21229429563721 is a prime.

It is not a weakly prime, because it can be changed into another prime (21229429567117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10614714783908 + 10614714783909.

It is an arithmetic number, because the mean of its divisors is an integer number (10614714783909).

Almost surely, 2^{21229429567817} is an apocalyptic number.

It is an amenable number.

21229429567817 is a deficient number, since it is larger than the sum of its proper divisors (1).

21229429567817 is an equidigital number, since it uses as much as digits as its factorization.

21229429567817 is an evil number, because the sum of its binary digits is even.

The product of its digits is 60963840, while the sum is 65.

The spelling of 21229429567817 in words is "twenty-one trillion, two hundred twenty-nine billion, four hundred twenty-nine million, five hundred sixty-seven thousand, eight hundred seventeen".