21416079309809 has 2 divisors, whose sum is σ = 21416079309810. Its totient is φ = 21416079309808.

The previous prime is 21416079309739. The next prime is 21416079309857. The reversal of 21416079309809 is 90890397061412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21064611744400 + 351467565409 = 4589620^2 + 592847^2 .

It is a cyclic number.

It is not a de Polignac number, because 21416079309809 - 2⁸ = 21416079309553 is a prime.

It is not a weakly prime, because it can be changed into another prime (21416079309899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10708039654904 + 10708039654905.

It is an arithmetic number, because the mean of its divisors is an integer number (10708039654905).

Almost surely, 2^{21416079309809} is an apocalyptic number.

It is an amenable number.

21416079309809 is a deficient number, since it is larger than the sum of its proper divisors (1).

21416079309809 is an equidigital number, since it uses as much as digits as its factorization.

21416079309809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5878656, while the sum is 59.

The spelling of 21416079309809 in words is "twenty-one trillion, four hundred sixteen billion, seventy-nine million, three hundred nine thousand, eight hundred nine".