21417812261009 has 2 divisors, whose sum is σ = 21417812261010. Its totient is φ = 21417812261008.

The previous prime is 21417812260987. The next prime is 21417812261057. The reversal of 21417812261009 is 90016221871412.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13981130548225 + 7436681712784 = 3739135^2 + 2727028^2 .

It is a cyclic number.

It is not a de Polignac number, because 21417812261009 - 2⁸ = 21417812260753 is a prime.

It is not a weakly prime, because it can be changed into another prime (21417812261099) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10708906130504 + 10708906130505.

It is an arithmetic number, because the mean of its divisors is an integer number (10708906130505).

Almost surely, 2^{21417812261009} is an apocalyptic number.

It is an amenable number.

21417812261009 is a deficient number, since it is larger than the sum of its proper divisors (1).

21417812261009 is an equidigital number, since it uses as much as digits as its factorization.

21417812261009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96768, while the sum is 44.

The spelling of 21417812261009 in words is "twenty-one trillion, four hundred seventeen billion, eight hundred twelve million, two hundred sixty-one thousand, nine".