409956435661 has 2 divisors, whose sum is σ = 409956435662. Its totient is φ = 409956435660.

The previous prime is 409956435659. The next prime is 409956435683. The reversal of 409956435661 is 166534659904.

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., 409607680036 + 348755625 = 640006^2 + 18675^2 .

It is a cyclic number.

It is not a de Polignac number, because 409956435661 - 2¹ = 409956435659 is a prime.

Together with 409956435659, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 409956435596 and 409956435605.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (409956435641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 204978217830 + 204978217831.

It is an arithmetic number, because the mean of its divisors is an integer number (204978217831).

Almost surely, 2^409956435661 is an apocalyptic number.

It is an amenable number.

409956435661 is a deficient number, since it is larger than the sum of its proper divisors (1).

409956435661 is an equidigital number, since it uses as much as digits as its factorization.

409956435661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20995200, while the sum is 58.

The spelling of 409956435661 in words is "four hundred nine billion, nine hundred fifty-six million, four hundred thirty-five thousand, six hundred sixty-one".