21470066073809 has 2 divisors, whose sum is σ = 21470066073810. Its totient is φ = 21470066073808.

The previous prime is 21470066073683. The next prime is 21470066073829. The reversal of 21470066073809 is 90837066007412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11763850443409 + 9706215630400 = 3429847^2 + 3115480^2 .

It is a cyclic number.

It is not a de Polignac number, because 21470066073809 - 2²⁴ = 21470049296593 is a prime.

It is not a weakly prime, because it can be changed into another prime (21470066073829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10735033036904 + 10735033036905.

It is an arithmetic number, because the mean of its divisors is an integer number (10735033036905).

Almost surely, 2^{21470066073809} is an apocalyptic number.

It is an amenable number.

21470066073809 is a deficient number, since it is larger than the sum of its proper divisors (1).

21470066073809 is an equidigital number, since it uses as much as digits as its factorization.

21470066073809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3048192, while the sum is 53.

The spelling of 21470066073809 in words is "twenty-one trillion, four hundred seventy billion, sixty-six million, seventy-three thousand, eight hundred nine".