20405335129 has 2 divisors, whose sum is σ = 20405335130. Its totient is φ = 20405335128.

The previous prime is 20405335117. The next prime is 20405335157. The reversal of 20405335129 is 92153350402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18079491600 + 2325843529 = 134460^2 + 48227^2 .

It is a cyclic number.

It is not a de Polignac number, because 20405335129 - 2¹⁹ = 20404810841 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20405335094 and 20405335103.

It is not a weakly prime, because it can be changed into another prime (20405335199) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10202667564 + 10202667565.

It is an arithmetic number, because the mean of its divisors is an integer number (10202667565).

Almost surely, 2^20405335129 is an apocalyptic number.

It is an amenable number.

20405335129 is a deficient number, since it is larger than the sum of its proper divisors (1).

20405335129 is an equidigital number, since it uses as much as digits as its factorization.

20405335129 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32400, while the sum is 34.

The spelling of 20405335129 in words is "twenty billion, four hundred five million, three hundred thirty-five thousand, one hundred twenty-nine".