21460642666249 has 2 divisors, whose sum is σ = 21460642666250. Its totient is φ = 21460642666248.

The previous prime is 21460642666247. The next prime is 21460642666289. The reversal of 21460642666249 is 94266624606412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21445864617024 + 14778049225 = 4630968^2 + 121565^2 .

It is a cyclic number.

It is not a de Polignac number, because 21460642666249 - 2¹ = 21460642666247 is a prime.

Together with 21460642666247, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 21460642666193 and 21460642666202.

It is not a weakly prime, because it can be changed into another prime (21460642666247) 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, 10730321333124 + 10730321333125.

It is an arithmetic number, because the mean of its divisors is an integer number (10730321333125).

Almost surely, 2^{21460642666249} is an apocalyptic number.

It is an amenable number.

21460642666249 is a deficient number, since it is larger than the sum of its proper divisors (1).

21460642666249 is an equidigital number, since it uses as much as digits as its factorization.

21460642666249 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 35831808, while the sum is 58.

The spelling of 21460642666249 in words is "twenty-one trillion, four hundred sixty billion, six hundred forty-two million, six hundred sixty-six thousand, two hundred forty-nine".