21010067457689 has 2 divisors, whose sum is σ = 21010067457690. Its totient is φ = 21010067457688.

The previous prime is 21010067457679. The next prime is 21010067457739. The reversal of 21010067457689 is 98675476001012.

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., 17200993118464 + 3809074339225 = 4147408^2 + 1951685^2 .

It is a cyclic number.

It is not a de Polignac number, because 21010067457689 - 2²⁴ = 21010050680473 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21010067457619) 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, 10505033728844 + 10505033728845.

It is an arithmetic number, because the mean of its divisors is an integer number (10505033728845).

Almost surely, 2^{21010067457689} is an apocalyptic number.

It is an amenable number.

21010067457689 is a deficient number, since it is larger than the sum of its proper divisors (1).

21010067457689 is an equidigital number, since it uses as much as digits as its factorization.

21010067457689 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5080320, while the sum is 56.

The spelling of 21010067457689 in words is "twenty-one trillion, ten billion, sixty-seven million, four hundred fifty-seven thousand, six hundred eighty-nine".