20409264171689 has 2 divisors, whose sum is σ = 20409264171690. Its totient is φ = 20409264171688.

The previous prime is 20409264171587. The next prime is 20409264171733. The reversal of 20409264171689 is 98617146290402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17675995544089 + 2733268627600 = 4204283^2 + 1653260^2 .

It is a cyclic number.

It is not a de Polignac number, because 20409264171689 - 2⁸ = 20409264171433 is a prime.

It is a super-2 number, since 2×20409264171689² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20409264171889) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10204632085844 + 10204632085845.

It is an arithmetic number, because the mean of its divisors is an integer number (10204632085845).

Almost surely, 2^{20409264171689} is an apocalyptic number.

It is an amenable number.

20409264171689 is a deficient number, since it is larger than the sum of its proper divisors (1).

20409264171689 is an equidigital number, since it uses as much as digits as its factorization.

20409264171689 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10450944, while the sum is 59.

The spelling of 20409264171689 in words is "twenty trillion, four hundred nine billion, two hundred sixty-four million, one hundred seventy-one thousand, six hundred eighty-nine".